Merge branch 'Redesign' of https://gitea.zuev.company/Zuev/magistr into Redesign

Поправил графики
.
2026-08-14 23:41:59 +03:00 · 2026-08-14 23:41:55 +03:00 · 2026-08-14 22:54:16 +03:00 · 2026-08-12 01:07:35 +03:00 · 2026-08-11 18:18:08 +03:00 · 2026-08-11 01:55:02 +03:00
156 changed files with 17897 additions and 1121 deletions
--- a/.gitea/workflows/docker-build.yaml
+++ b/.gitea/workflows/docker-build.yaml
@@ -183,7 +183,6 @@ jobs:
  deploy-to-k8s:
    name: Развернуть проверенные digests
    needs: [build-and-push-backend, build-and-push-frontend, security-scan]
-    if: ${{ gitea.event_name == 'workflow_dispatch' }}
    runs-on: ubuntu-latest
    timeout-minutes: 15
    environment: production
--- a/AI_ASSISTANT_IMPLEMENTATION_PLAN.md
+++ b/AI_ASSISTANT_IMPLEMENTATION_PLAN.md
--- a/DEVOPS.md
+++ b/DEVOPS.md
@@ -1,292 +0,0 @@
-# РАЗРАБОТКА И ВНЕДРЕНИЕ ОТКАЗОУСТОЙЧИВОЙ МУЛЬТИТЕНАНТНОЙ ИНФРАСТРУКТУРЫ ДЛЯ СИСТЕМЫ УПРАВЛЕНИЯ УНИВЕРСИТЕТСКИМ РАСПИСАНИЕМ «МАГИСТР»
-
-**Диссертационное исследование и отчет о проделанной инженерной работе в качестве DevOps-архитектора проекта**
-
---
-
-## ВВЕДЕНИЕ
-
-Современные информационные системы для образовательных учреждений требуют строгого соблюдения требований к безопасности, изоляции данных различных организаций (университетов), гибкости масштабирования и высокой наблюдаемости (observability). В рамках разработки проекта **«Магистр»** — системы управления расписанием учебных занятий — передо мной встала задача проектирования и построения инфраструктуры, способной обслуживать десятки университетов в рамках единого прикладного контура при условии жесткой изоляции их баз данных.
-
-В качестве DevOps-инженера проекта я спроектировал и реализовал архитектурное решение, объединяющее технологии аппаратной виртуализации, оркестрации контейнеров, автоматизации конфигурации, распределенного мониторинга и непрерывной интеграции. В данном документе подробно описаны теоретические предпосылки, практическая реализация и архитектурные решения, внедренные мной в продакшн-окружение проекта.
-
---
-
-## РАЗДЕЛ 1. СИСТЕМНАЯ АРХИТЕКТУРА И КОНЦЕПЦИЯ МУЛЬТИТЕНАНТНОСТИ
-
-### 1.1 Выбор паттерна изоляции данных
-При проектировании мультитенантных (multi-tenant) систем классически выделяют три подхода к организации баз данных:
-1. **Shared Database & Shared Schema**: Все клиенты используют общие таблицы, записи разделяются по полю `tenant_id`. Подход дешев в обслуживании, но несет колоссальные риски утечки данных из-за ошибок в SQL-запросах приложения и не позволяет разграничивать физический доступ к базам.
-2. **Shared Database & Separate Schemas**: Одна СУБД, но разные логические схемы для каждого клиента. Обеспечивает умеренную изоляцию, но сохраняет единую точку отказа и общие аппаратные ресурсы СУБД.
-3. **Database-per-Tenant (Выбранный подход)**: Каждый клиент (университет) владеет собственной физически изолированной базой данных, расположенной на выделенном сервере или виртуальной машине.
-
-Для проекта «Магистр» мной был выбран и реализован паттерн **Database-per-Tenant**. Это обусловлено спецификой клиентов (высшие учебные заведения), которые согласно законодательству (например, ФЗ-152 «О персональных данных») обязаны хранить свои данные локально или требовать полной изоляции конфиденциальной информации. Кроме того, данный подход позволяет:
-* Исключить влияние высокой нагрузки одного университета (например, в период составления сессий) на доступность системы для других вузов («синдром шумного соседа»).
-* Выполнять индивидуальное резервное копирование и обслуживание БД каждого университета без остановки всей платформы.
-* Переносить базы данных вузов на их собственные физические серверы в локальных сетях (on-premise), сохраняя при этом работу приложения в центральном облаке.
-
-### 1.2 Архитектурная схема движения трафика
-Ниже представлена разработанная мной схема прохождения сетевых запросов и агрегации телеметрии в системе:
-
-```mermaid
-graph TD
-    Client[Пользовательский браузер] -->|HTTPS: tenant.zuev.company| Caddy[Caddy Reverse Proxy]
-    Caddy -->|HTTP Round-Robin| Ingress[Traefik Ingress Controller]
-    
-    subgraph K3s Cluster
-        Ingress -->|Route /*| Frontend[Frontend Pods x2 Apache]
-        Ingress -->|Route /api/*| Backend[Backend Pods x1-x2 Spring Boot]
-        Backend -->|K8s API: Get/Patch CM| K8sAPI[Kubernetes API Server]
-        BackendConfig[ConfigMap: tenants-config] -.->|Mounted JSON| Backend
-    end
-    
-    subgraph Proxmox VE Infrastructure
-        Backend -->|JDBC Connection| VM1[(VM 1: DBMS MSU<br>PostgreSQL 16)]
-        Backend -->|JDBC Connection| VM2[(VM 2: DBMS SWSU<br>PostgreSQL 16)]
-        
-        VM1 -.->|Metrics OTLP/gRPC| Collector1[OTel Collector VM1]
-        VM2 -.->|Metrics OTLP/gRPC| Collector2[OTel Collector VM2]
-    end
-
-    subgraph Observability Hub
-        Backend -->|Logs & Traces OTLP| SigNoz[SigNoz APM Server]
-        Collector1 -->|Postgres Metrics| SigNoz
-        Collector2 -->|Postgres Metrics| SigNoz
-    end
-    
-    classDef cluster fill:#e1f5fe,stroke:#01579b,stroke-width:2px;
-    classDef vm fill:#efebe9,stroke:#4e342e,stroke-width:2px;
-    classDef monitor fill:#efe8ff,stroke:#512da8,stroke-width:2px;
-    class K3s Cluster cluster;
-    class Proxmox VE Infrastructure vm;
-    class Observability Hub monitor;
-```
-
---
-
-## РАЗДЕЛ 2. АППАРАТНАЯ ВИРТУАЛИЗАЦИЯ НА БАЗЕ PROMVOX VE
-
-Для размещения баз данных клиентов и вспомогательных инфраструктурных служб мной был развернут гипервизор **Proxmox Virtual Environment (PVE)** на выделенных серверных мощностях.
-
-### 2.1 Конфигурация виртуализации и изоляции ресурсов
-Каждая база данных университета разворачивается в выделенной виртуальной машине (KVM), что гарантирует жесткую изоляцию на уровне ядра ОС и гипервизора.
-* **Сетевой уровень**: В Proxmox настроена виртуальная коммутация (Linux Bridge `vmbr0`). Сетевые интерфейсы виртуальных машин баз данных вынесены в приватную подсеть, изолированную от внешней сети. Доступ к ним имеет только подсеть кластера Kubernetes и управляющая машина администратора.
-* **Дисковая подсистема**: Использовано локальное хранилище на базе ZFS с зеркалированием (RAID-10 на SSD-накопителях). Это обеспечивает:
-  * Высокую скорость операций ввода-вывода (IOPS), критически важную для СУБД при транзакционных нагрузках.
-  * Механизм мгновенных снимков (snapshots) для безопасного проведения обновлений.
-  * Аппаратное сжатие данных (LZ4) без потери производительности, снижающее износ накопителей.
-* **Резервное копирование**: Интегрирован **Proxmox Backup Server (PBS)**. Каждую ночь выполняются инкрементальные бэкапы виртуальных машин с дедупликацией на уровне блоков данных, что минимизирует нагрузку на сеть и диски, позволяя восстановить любую БД на любой момент времени за последние 30 дней.
-
---
-
-## РАЗДЕЛ 3. ОРКЕСТРАЦИЯ КОНТЕЙНЕРНОЙ ИНФРАСТРУКТУРЫ В KUBERNETES (K3s)
-
-В качестве платформы оркестрации приложений был выбран **K3s** — сертифицированный дистрибутив Kubernetes от Rancher, оптимизированный под средние и малые нагрузки, обладающий минимальными накладными расходами на RAM/CPU для Control Plane, но сохраняющий полную совместимость с upstream-спецификациями Kubernetes API.
-
-### 3.1 Архитектура манифестов и структура ресурсов
-Мной была разработана декларативная структура ресурсов, развернутая в изолированном пространстве имен `magistr` (манифест `namespace.yaml`):
-
-* **Frontend (`frontend.yaml`)**:
-  * Реализован в виде `Deployment` с 2 репликами для обеспечения высокой доступности (HA) и возможности бесшовного обновления rolling-update.
-  * В качестве базового образа контейнера применен легковесный веб-сервер Apache HTTPd; версия и manifest digest закреплены в Dockerfile.
-  * Для балансировки и внутреннего доступа настроен `Service` типа ClusterIP, слушающий порт 80.
-  
-* **Backend (`backend.yaml`)**:
-  * `Deployment` с 1-2 репликами (детали балансировки конфигурации описаны ниже).
-  * Для сборки образов используется multi-stage сборка Maven (JDK 17); build/runtime-образы одновременно закреплены точным tag и manifest digest.
-  * Интегрирован Java-агент OpenTelemetry для автоматического инструментирования трассировки и логов.
-  * Для связи с Ingress настроен ClusterIP-сервис на порту 8080.
-  
-* **Ingress (`ingress.yaml`)**:
-  * В роли Ingress-контроллера выступает встроенный **Traefik** (`kube-system/traefik`).
-  * Он доступен извне через Klipper Service LoadBalancer (DaemonSet), который прокидывает порты 80/443 (hostPort) на внешние IP адреса нод кластера (`192.168.1.104`, `192.168.1.105`, `192.168.1.106`).
-  * Мной настроены строгие правила маршрутизации по доменным именам (например, `magistr.zuev.company` и `n8n.zuev.company`). Запросы к API (`/api`) проксируются на бэкенд, а к корню (`/`) — на фронтенд.
-
-### 3.2 Реализация динамической мультитенантности через K8s API
-Одним из наиболее сложных этапов проектирования стала организация бесшовного добавления новых университетов без перезапуска бэкенда и изменения исходного кода приложения.
-
-1. **Хранение конфигурации**:
-   Список подключений к базам данных университетов хранится в JSON-формате (`tenants.json`) внутри Kubernetes `ConfigMap` с именем `tenants-config`.
-
-2. **Проблема Read-Only монтирования**:
-   По умолчанию Kubernetes монтирует ConfigMap как файловую систему в режиме Read-Only. Это исключало возможность для Java-приложения перезаписывать `tenants.json` при запросах от администратора на добавление нового тенанта.
-   
-3. **Решение с использованием `initContainer` и `emptyDir`**:
-   Я спроектировал схему с временным перезаписываемым томом (`emptyDir`):
-   * В спецификацию пода backend добавлен `initContainer` на базе образа `busybox`.
-   * При старте пода `initContainer` монтирует ConfigMap `tenants-config` и копирует файл `tenants.json` во временный раздел `emptyDir` (путь `/config`).
-   * Основной контейнер `backend` монтирует этот же `emptyDir` в режиме Read-Write.
-
-4. **K8s RBAC и динамическое сохранение**:
-   Чтобы предоставить бэкенду возможность сохранять изменения конфигурации обратно в кластер, мной были написаны манифесты авторизации (`rbac.yaml`):
-   * Создан `ServiceAccount` `backend-sa` и назначен поду бэкенда.
-   * Описана Kubernetes `Role` `backend-configmap-role`, дающая права только на операции `get` и `patch` для ресурса `configmaps` с конкретным именем `tenants-config` (принцип наименьших привилегий).
-   * Создан `RoleBinding` `backend-configmap-binding`, связывающий сервис-аккаунт с этой ролью.
-   
-   В коде бэкенда класс `ConfigMapUpdater` через Kubernetes Java Client отправляет PATCH-запрос к API-серверу при добавлении нового тенанта, обновляя ConfigMap в самом кластере.
-
-5. **Репликация и синхронизация подов**:
-   Для обеспечения консистентности данных в условиях работы нескольких реплик бэкенда:
-   * Класс `TenantConfigWatcher` запускает фоновую задачу, которая каждые 30 секунд сверяет MD5-хеш локального файла `tenants.json` с версией из ConfigMap.
-   * При обнаружении расхождения файл перезаписывается, DataSource-инстансы пересоздаются в памяти приложения на лету, исключая рассинхронизацию подов.
-   * *Примечание*: В ходе тестирования для минимизации задержек и исключения эффекта "мигания" данных на время отладки количество реплик backend было ограничено до 1, с последующим переходом на полноценный StatefulSet/Shared Storage при росте количества нод.
-
-### 3.3 Повышение отказоустойчивости бэкенда (Resiliency)
-При запуске бэкенда в облаке возникала проблема: если база данных одного из университетов становилась недоступной (например, из-за сетевого сбоя или регламентных работ), пул подключений HikariCP падал с ошибкой при инициализации бинов, отправляя под бэкенда в циклическую перезагрузку (`CrashLoopBackOff`), что делало недоступной систему для *всех* остальных вузов.
-
-Для предотвращения этого каскадного сбоя я внедрил комплекс защитных механизмов:
-* **H2 Fallback**: В сборку (`pom.xml`) добавлена СУБД H2 in-memory. Если при старте ConfigMap пуст, Spring Boot инициализирует пустой JPA-контекст на базе H2, что позволяет приложению успешно пройти фазу запуска.
-* **HikariCP Resiliency**: В конфигурации источников данных задано свойство `setInitializationFailTimeout(-1)`. Это заставляет HikariCP игнорировать отсутствие связи с целевой БД при старте приложения, продолжая попытки подключения в фоновом режиме.
-* **Явное указание диалекта Hibernate**: Принудительно задан `org.hibernate.dialect.PostgreSQLDialect` в `TenantDataSourceConfig.java`. Это избавило Hibernate от необходимости выполнять тестовый запрос к БД для автоматического определения диалекта на ранних этапах инициализации контекста.
-* **Автоматическое создание таблиц (`DataInitializer`)**: Для новых БД вузов полностью автоматизирован процесс наката структуры. При обнаружении новой базы Java-код проверяет наличие таблицы `users` и, в случае ее отсутствия, самостоятельно применяет SQL-скрипт инициализации (`init.sql`), включая создание дефолтных справочников и учетной записи суперадминистратора.
-
---
-
-## РАЗДЕЛ 4. АВТОМАТИЗАЦИЯ КОНФИГУРАЦИИ СУБД С ПОМОЩЬЮ ANSIBLE
-
-Для развертывания и администрирования баз данных университетов на удаленных виртуальных машинах Proxmox мной был спроектирован и реализован комплексный плейбук **Ansible** с модульной структурой ролей.
-
-### 4.1 Структура и функционал Ansible-ролей
-Вся конфигурация целевого сервера разбита на 6 последовательных этапов (плейбук `site.yml`):
-
-1. **`common` (Базовая подготовка и Hardening ОС)**:
-   * Создание системного пользователя `deploy` с беспарольным доступом к `sudo` (через валидацию файла `/etc/sudoers.d/deploy` утилитой `visudo`).
-   * Установка системных утилит (`curl`, `git`, `htop`, `chrony` для синхронизации времени по NTP).
-   * **SSH Hardening**: Изменение стандартного SSH-порта на `2222`, отключение авторизации по паролям, запрет входа для пользователя `root`, ограничение таймаута сессий.
-   * Адаптация под различные дистрибутивы ОС: написаны отдельные сценарии для семейств Debian/Ubuntu/Astra Linux (пакетный менеджер `apt`), RedHat/РЕД ОС (`dnf`) и ALT Linux (кастомная обертка для `apt-get`).
-
-2. **`docker` (Среда контейнеризации)**:
-   * Автоматическое добавление официальных GPG-ключей и репозиториев Docker CE.
-   * Установка Docker Engine, CLI и Compose плагина.
-   * Включение системной службы `docker` и добавление пользователя `deploy` в группу `docker` для беспарольного запуска контейнеров.
-
-3. **`firewall` (Сетевая безопасность)**:
-   * Настройка межсетевого экрана UFW (для Debian-based систем) или firewalld (для RedHat и ALT Linux).
-   * Полная блокировка входящего трафика по умолчанию.
-   * Разрешение входящих пакетов только на порт SSH (`2222`) и порт PostgreSQL (`5432`). Реализована поддержка ограничения доступа к порту `5432` только для IP-адресов нод Kubernetes-кластера (`firewall_postgresql_allowed_ips`).
-
-4. **`postgresql` (Контейнеризированная СУБД)**:
-   * Генерация файлов конфигурации `docker-compose.yml` и `.env` на основе шаблонов Jinja2.
-   * Развертывание PostgreSQL 16 на базе легковесного Alpine-образа.
-   * Физическое монтирование каталога данных БД с хост-системы (`/opt/magistr/postgres/data`), предотвращающее потерю данных при пересоздании контейнера.
-   * Ограничение системных ресурсов контейнера (limits: memory: 512M) и тюнинг параметров PostgreSQL (`shared_buffers=256MB`, оптимизация пула соединений, логирование медленных запросов `log_min_duration_statement=1000`).
-
-5. **`backup` (Резервное копирование на уровне БД)**:
-   * Установка на хост автоматического bash-скрипта бэкапа.
-   * Настройка задачи `cron` (запуск ежедневно в 03:00).
-   * Скрипт осуществляет горячий дамп базы через `docker exec pg_dump`, архивирует его с помощью `gzip` и сохраняет в локальный каталог `/opt/magistr/backups/`.
-   * Реализован алгоритм автоматической ротации: удаление архивных файлов старше заданного количества дней (по умолчанию 14 дней).
-
-6. **`monitoring` (Сбор телеметрии хоста и БД)**:
-   * Развертывание контейнера OpenTelemetry Collector на целевом сервере БД.
-   * Конфигурирование коллектора на сбор метрик производительности PostgreSQL и ОС (процессор, память, диски) и их отправку на единый сервер SigNoz по OTLP/HTTP.
-
-### 4.2 Управление секретами: Ansible Vault
-Для исключения попадания паролей администраторов БД в систему контроля версий (Git) все чувствительные переменные (например, `vault_postgresql_password`) вынесены в файл `group_vars/databases/vault.yml` и зашифрованы алгоритмом AES-256 с помощью **Ansible Vault**.
-
-Для бесшовной интеграции в CI/CD пароль расшифрования считывается из локального файла `.vault_pass` на управляющей машине, доступ к которому ограничен правами `chmod 600`.
-
---
-
-## РАЗДЕЛ 5. НЕПРЕРЫВНАЯ ИНТЕГРАЦИЯ И ДОСТАВКА (CI/CD)
-
-В рамках оптимизации внутренних процессов разработки и деплоя мной была развернута и настроена инфраструктура непрерывной интеграции на базе **Gitea** и **Gitea Actions**.
-
-### 5.1 Автоматизация сборки (CI)
-В репозитории проекта создан workflow-манифест `.gitea/workflows/docker-build.yaml`. При каждом пуше изменений в ветку `main` запускается конвейер:
-1. **Checks**: Backend/frontend-тесты, Compose validation, тест immutable rollback и статическая проверка закрепления артефактов.
-2. **Build & Push**: Параллельная сборка и публикация backend/frontend с SHA-tag или release tag; mutable `latest` не создаётся.
-3. **Attestations**: BuildKit добавляет к обоим образам SBOM и максимальную provenance-attestation.
-4. **Security scan**: Закреплённый digest Trivy блокирует доставку при исправимых уязвимостях `HIGH`/`CRITICAL`.
-5. **Deploy**: Только прошедшие gates registry digests передаются в production rollout. Все сторонние Actions закреплены полными commit SHA.
-
-### 5.2 Доставка в кластер (CD)
-Для авторизации нод K3s в приватном реестре Gitea мной был создан секрет `gitea-registry` типа `docker-registry` в пространстве имен `magistr`. Этот секрет ассоциирован со спецификациями деплоев через директиву `imagePullSecrets`.
-
-Непосредственно Gitea Actions Runner работает как демон `act_runner` внутри изолированного LXC контейнера (CTID 107). В пайплайне шаг развертывания (`deploy-to-k8s`) динамически генерирует `kubeconfig` из секрета, проверяет checksum закреплённой версии `kubectl` и выполняет атомарное обновление обоих образов без использования тяжеловесных GitOps операторов:
-
-```bash
-bash scripts/deploy-images.sh \
-  gitea.zuev.company/zuev/magistr-backend@sha256:<digest> \
-  gitea.zuev.company/zuev/magistr-frontend@sha256:<digest>
-```
-
-Скрипт принимает только полные `image@sha256:...`, ожидает готовность обоих Deployment и при
-ошибке возвращает предыдущую пару digest. Поэтому содержимое релиза не зависит от повторного
-разрешения mutable tag.
-
---
-
-## РАЗДЕЛ 6. ВХОДНОЙ ПРОКСИ-СЕРВЕР НА БАЗЕ CADDY PROXY
-
-Для маршрутизации внешнего трафика и защиты соединений на входе в инфраструктуру развернут веб-сервер **Caddy**.
-
-### 6.1 Преимущества Caddy и управление SSL/TLS
-В отличие от классического Nginx, Caddy был выбран благодаря:
-* Встроенной интеграции с удостоверяющими центрами Let's Encrypt и ZeroSSL. При добавлении нового поддомена вуза (например, `swsu.zuev.company`) Caddy автоматически запрашивает, валидирует через DNS/HTTP-вызовы и устанавливает TLS-сертификат, а также следит за его продлением.
-* Лаконичному синтаксису конфигурации (`Caddyfile`).
-* Полноценной поддержке протокола HTTP/3 «из коробки».
-
-### 6.2 Конфигурация балансировки
-Внешний Caddy-сервер развернут в изолированном LXC контейнере (CTID 101) и обрабатывает запросы ко всем поддоменам проекта. Он перенаправляет их на ноды кластера K3s, выполняя роль внешнего балансировщика, а также проксирует телеметрию с фронтенда напрямую в сборщик OTel:
-
-```caddyfile
-(otel_proxy) {
-  handle_path /otel/* { reverse_proxy 192.168.1.100:4318 }
-}
-
-(k8s_nodes) {
-  handle {
-    reverse_proxy 192.168.1.104:80 192.168.1.105:80 192.168.1.106:80 {
-      lb_policy round_robin
-      lb_try_duration 5s
-      lb_try_interval 250ms
-    }
-  }
-}
-
-magistr.zuev.company { import otel_proxy; import k8s_nodes }
-n8n.zuev.company { import otel_proxy; import k8s_nodes }
-```
-Сетевые запросы к приложениям распределяются по 3 физическим нодам K3s. Благодаря сниппетам, добавление нового тенанта в инфраструктуре Caddy требует всего двух строчек конфигурации.
-
---
-
-## РАЗДЕЛ 7. СКВОЗНОЙ МОНИТОРИНГ И ОБСЕРВАБИЛИТИ (SigNoz + OpenTelemetry)
-
-Для контроля здоровья системы и оперативного выявления аномалий мной была спроектирована и внедрена централизованная система мониторинга на базе APM-платформы **SigNoz** (с хранилищем **ClickHouse**) и стандартов **OpenTelemetry (OTel)**. 
-
-Платформа SigNoz вынесена в отдельный LXC контейнер (CTID 100) по адресу `192.168.1.100` и развернута через `docker-compose`. Данные ClickHouse и SQLite метаданные персистентно хранятся в Docker volumes хоста для обеспечения сохранности при рестартах.
-
-### 7.1 Сбор телеметрии Backend
-Java-приложение бэкенда запускается с подключением агента OpenTelemetry (`opentelemetry-javaagent.jar`). Это позволяет без изменения кода собирать:
-* **Трейсы (Traces)**: Сквозное прохождение HTTP-запросов через контроллеры, сервисы и JDBC-драйвер к базам данных.
-* **Метрики (Metrics)**: Метрики JVM (утилизация Heap, активность сборщика мусора GC, состояние потоков), метрики HTTP-запросов (интенсивность, латентность, коды ответов).
-* **Логи (Logs)**: Системные логи Logback экспортируются по протоколу OTLP напрямую в SigNoz.
-
-### 7.2 Идентификация тенантов в мониторинге
-Для глубокого анализа производительности СУБД конкретных университетов критически важно разделять телеметрию по тенантам. Мной была реализована сквозная маркировка:
-* В бэкенде через Java-интерцептор `TenantInterceptor` при каждом запросе идентификатор тенанта помещается в контекст логирования SLF4J MDC (`MDC.put("tenant.id", tenant)`) и одновременно записывается в атрибуты текущего OpenTelemetry спана (`Span.current().setAttribute("tenant.id", tenant)`).
-* Благодаря переменной окружения `OTEL_INSTRUMENTATION_LOGBACK_APPENDER_EXPERIMENTAL_CAPTURE_MDC_ATTRIBUTES=tenant.id`, OTel-агент автоматически парсит MDC и прикрепляет его к логам, отправляемым в SigNoz. Это позволяет администраторам фильтровать ошибки и строить графики нагрузки в разрезе каждого университета.
-
-### 7.3 Мониторинг баз данных на хостах
-Для сбора детальной статистики с изолированных серверов баз данных:
-1. На хостах БД силами Ansible разворачивается OpenTelemetry Collector.
-2. В конфигурации коллектора (`otel-collector-config.yml.j2`) описывается ресивер `postgresql`, который подключается к локальной БД и считывает системные метрики (размер таблиц, cache hit ratio, количество транзакций, активные сессии, блокировки).
-3. К собираемым метрикам жестко прикрепляются ресурсные атрибуты хоста: `service.name=magistr-db-<tenant_domain>` и `university.name=<University Name>`.
-4. Метрики экспортируются в центральный коллектор SigNoz. В результате в интерфейсе SigNoz доступны кастомные дашборды JVM, PostgreSQL и HTTP, позволяющие оперативно локализовать проблемы с производительностью баз данных конкретных вузов.
-
---
-
-## ЗАКЛЮЧЕНИЕ
-
-Разработанная и внедренная мной DevOps-архитектура для проекта «Магистр» успешно решила задачи изоляции данных, отказоустойчивости и автоматизации администрирования. 
-
-### Ключевые результаты проделанной работы:
-1. **Изоляция данных**: Реализована физическая изоляция БД университетов на выделенных серверах (VM в Proxmox VE), соответствующая требованиям безопасности и законодательства.
-2. **Динамическое масштабирование**: Внедрен механизм динамического добавления тенантов без простоя системы (zero-downtime) за счет связки Spring Boot, K8s RBAC и ConfigMapWatcher.
-3. **Отказоустойчивость**: Минимизированы риски каскадных сбоев бэкенда за счет применения in-memory fallback баз данных и оптимизации параметров подключения HikariCP.
-4. **Автоматизация**: Создан универсальный Ansible-плейбук для быстрого ввода в эксплуатацию новых серверов БД (время развертывания «под ключ» сокращено до нескольких минут).
-5. **Наблюдаемость**: Реализован сквозной мониторинг логов, метрик и трассировок с детализацией по тенантам на базе стека OpenTelemetry + SigNoz.
-
-Созданная инфраструктура обладает высокой степенью гибкости и готова к дальнейшему горизонтальному масштабированию по мере подключения новых высших учебных заведений к проекту «Магистр».
--- a/STARTUP_GUIDE.md
+++ b/STARTUP_GUIDE.md
@@ -1,160 +0,0 @@
-# Инструкция запуска Magistr
-
-Ниже — минимальный порядок действий. Подробности по инфраструктуре и секретам находятся в
-[`docs/INFRASTRUCTURE.md`](docs/INFRASTRUCTURE.md) и
-[`docs/SECURITY_RUNBOOK.md`](docs/SECURITY_RUNBOOK.md).
-
-## 1. Локальный запуск
-
-Нужны Git, Docker Engine, Docker Compose и запущенный Caddy из `../сaddy-proxy/`.
-
-1. В корне проекта создайте локальный файл настроек:
-
-   ```bash
-   cp .env.example .env
-   openssl rand -base64 36   # значение POSTGRES_PASSWORD
-   openssl rand -base64 48   # значение JWT_SECRET
-   ```
-
-   Вставьте полученные значения в `.env`. Файл `.env` не коммитьте.
-
-2. Один раз создайте общую Docker-сеть, затем запустите Caddy и Magistr:
-
-   ```bash
-   docker network inspect proxy >/dev/null 2>&1 || docker network create proxy
-   docker compose -f ../сaddy-proxy/compose.yaml up -d
-   docker compose config --quiet
-   docker compose up -d --build
-   docker compose ps
-   ```
-
-3. Откройте `https://localhost` (`http://localhost` перенаправит на HTTPS). Проверьте backend
-   через Caddy:
-
-   ```bash
-   curl -kfsS https://localhost/actuator/health/readiness
-   ```
-
-   Если браузер не доверяет локальному сертификату Caddy, на CachyOS/Arch выполните:
-
-   ```bash
-   docker cp caddy:/data/caddy/pki/authorities/local/root.crt /tmp/caddy-local-root.crt
-   sudo trust anchor --store /tmp/caddy-local-root.crt
-   ```
-
-   До установки проверьте SHA-256 отпечаток командой
-   `openssl x509 -in /tmp/caddy-local-root.crt -noout -fingerprint -sha256`, затем полностью
-   перезапустите браузер.
-
-   Для первого локального входа: `admin` / `admin`. Эти данные предназначены только для
-   разработки.
-
-4. Если запуск не удался:
-
-   ```bash
-   docker compose logs --tail=200 backend db frontend
-   ```
-
-   Полный локальный сброс БД выполняется командой `docker compose down -v`, но она удалит
-   все локальные данные. Обычная остановка без удаления данных: `docker compose down`.
-
-## 2. Обновление существующего production
-
-Простой push в `main` для первого обновления **недостаточен**. Он выполняет проверки,
-собирает и сканирует образы, но job `deploy-to-k8s` запускается только вручную через
-`workflow_dispatch`. Новые файлы `../k8s` CI не применяет. Gitea 1.25 игнорирует
-`environment` и `concurrency`, поэтому они не используются как production-защита.
-
-1. Подготовьте секреты по [`docs/SECURITY_RUNBOOK.md`](docs/SECURITY_RUNBOOK.md):
-
-   - `app-secret`: новый случайный `JWT_SECRET` не короче 32 байт, `POSTGRES_USER`,
-     `POSTGRES_PASSWORD`;
-   - `tenants-secret`: новый `tenants.json` с актуальными JDBC URL и ротированными паролями;
-   - `otel-postgres-secret`: восемь обязательных параметров подключений Collector;
-   - `gitea-registry`: доступ K3s к registry.
-
-   Для `magistr.zuev.company` нужен tenant с `"domain": "magistr"`, для
-   `n8n.zuev.company` — `"domain": "n8n"`. Секреты не сохраняйте в Git или CI-логах.
-
-2. Выполните локальные проверки, затем отправьте изменения в `main`:
-
-   ```bash
-   K8S_DIR=../k8s bash scripts/check-production-secrets.sh
-   K8S_DIR=../k8s bash scripts/check-artifact-pinning.sh
-   bash scripts/test-deploy-images.sh
-   kubectl kustomize ../k8s >/dev/null
-   ```
-
-   Дождитесь успешных checks, сборки и Trivy scan. Скопируйте точные backend/frontend
-   ссылки вида `image@sha256:...` из CI/registry.
-
-3. Объявите техническое окно и временно закройте публичный доступ во внешнем Caddy. Затем
-   остановите backend:
-
-   ```bash
-   kubectl scale deployment/backend -n magistr --replicas=0
-   ```
-
-   Полностью пересоздайте **каждую** PostgreSQL tenant-БД, указанную в новом
-   `tenants.json`. Недостаточно удалить `flyway_schema_history` или отдельные таблицы:
-   миграции V2–V7 объединены в новую `V1__init.sql`, поэтому старая БД получит checksum
-   error, а непустая БД без истории может быть ошибочно принята Flyway за baseline.
-   Пользователь БД должен уметь создавать схему, функции, триггеры и расширения
-   `pgcrypto`/`btree_gist`.
-
-4. С рабочей станции с актуальным каталогом `../k8s` выполните первый rollout вручную:
-
-   ```bash
-   export BACKEND_IMAGE_REF='gitea.zuev.company/zuev/magistr-backend@sha256:<digest>'
-   export FRONTEND_IMAGE_REF='gitea.zuev.company/zuev/magistr-frontend@sha256:<digest>'
-   bash ../k8s/deploy.sh apply
-   ```
-
-   Скрипт применит ConfigMap, RBAC, Secret mount, probes, OTel и Ingress, поднимет две
-   реплики backend и дождётся Flyway/readiness. CI deploy после push не ожидает
-   подтверждения: он будет пропущен. Следующие image-only обновления можно запускать
-   вручную кнопкой `Run workflow`.
-
-5. Перед открытием публичного доступа проверьте:
-
-   ```bash
-   kubectl rollout status deployment/backend -n magistr --timeout=300s
-   kubectl rollout status deployment/frontend -n magistr --timeout=120s
-   kubectl get pods -n magistr
-   kubectl logs -n magistr -l app=backend --tail=200
-   curl -fsSI https://magistr.zuev.company/
-   ```
-
-   Проверьте в браузере login → reload → refresh → logout для каждого tenant-домена.
-   Refresh-cookie должна иметь `HttpOnly`, `Secure`, `SameSite=Lax`, path `/api/auth`;
-   access JWT не должен находиться в Local/Session Storage. До снятия технического окна
-   смените или отключите все демонстрационные учётные записи из `V1__init.sql`.
-
-6. После проверки удалите старый `ConfigMap/tenants-config`, отзовите старые DB/OTel
-   пароли и верните обычный доступ через Caddy. В дальнейшем image-only изменения можно
-   разворачивать ручным запуском workflow, но любые изменения `../k8s` по-прежнему нужно
-   применять отдельно или переносить этот каталог в управляемый CI репозиторий.
-
-### Важные ограничения rollback
-
- Смена `JWT_SECRET` и сброс БД завершат все старые пользовательские сессии.
- Readiness требует доступности и успешной миграции всех tenant-БД; одна старая или
-  недоступная БД остановит rollout.
- Автоматический rollback возвращает только два image reference. Он не откатывает БД,
-  Secret, ConfigMap или RBAC; после применения новой V1 безопаснее исправлять проблему
-  вперёд либо снова пересоздавать БД под старую версию.
- CI не запускает Testcontainers integration tests: полный PostgreSQL-прогон нужно
-  повторить вручную, если после зафиксированных 300 успешных тестов код ещё менялся.
- `TRUSTED_PROXY_CIDRS=10.42.0.0/16` соответствует текущей pod-сети K3s. При смене
-  cluster CIDR его нужно обновить, иначе rate limit увидит неверные клиентские IP.
-
-## 3. Что могу выполнить я
-
-По вашей команде я могу подготовить `.env`, запустить и диагностировать локальный Compose,
-проверить/исправить код и манифесты, прогнать тесты и dry-run Kubernetes, а при доступном
-`kubectl` — проверить состояние кластера.
-
-Без вас я не могу получить реальные пароли и токены, настроить DNS/сертификаты у внешнего
-провайдера или войти в Gitea/Kubernetes, если доступы не предоставлены. Production deploy,
-ротацию Secret и удаление БД я не выполняю без отдельного явного разрешения: это меняет
-внешнюю систему и может прервать работу либо уничтожить данные.
--- a/backend/src/main/java/com/magistr/app/controller/AcademicCalendarAdminController.java
+++ b/backend/src/main/java/com/magistr/app/controller/AcademicCalendarAdminController.java
@@ -21,20 +21,20 @@ public class AcademicCalendarAdminController {
    private final AcademicYearRepository academicYearRepository;
    private final SemesterRepository semesterRepository;
    private final AcademicCalendarActivityTypeRepository activityTypeRepository;
-    private final AcademicCalendarDayRepository calendarDayRepository;
+    private final AcademicCalendarPeriodRepository calendarPeriodRepository;
    private final ScheduleGeneratorService scheduleGeneratorService;
    private final AcademicPeriodService academicPeriodService;

    public AcademicCalendarAdminController(AcademicYearRepository academicYearRepository,
                                           SemesterRepository semesterRepository,
                                           AcademicCalendarActivityTypeRepository activityTypeRepository,
-                                           AcademicCalendarDayRepository calendarDayRepository,
+                                           AcademicCalendarPeriodRepository calendarPeriodRepository,
                                           ScheduleGeneratorService scheduleGeneratorService,
                                           AcademicPeriodService academicPeriodService) {
        this.academicYearRepository = academicYearRepository;
        this.semesterRepository = semesterRepository;
        this.activityTypeRepository = activityTypeRepository;
-        this.calendarDayRepository = calendarDayRepository;
+        this.calendarPeriodRepository = calendarPeriodRepository;
        this.scheduleGeneratorService = scheduleGeneratorService;
        this.academicPeriodService = academicPeriodService;
    }
@@ -128,7 +128,7 @@ public class AcademicCalendarAdminController {
        if (!activityTypeRepository.existsById(id)) {
            return ResponseEntity.notFound().build();
        }
-        if (calendarDayRepository.existsByActivityTypeId(id)) {
+        if (calendarPeriodRepository.existsByActivityTypeId(id)) {
            return ResponseEntity.badRequest().body(Map.of("message", "Код активности используется в календарных графиках"));
        }
        activityTypeRepository.deleteById(id);
--- a/backend/src/main/java/com/magistr/app/controller/AcademicCalendarController.java
+++ b/backend/src/main/java/com/magistr/app/controller/AcademicCalendarController.java
@@ -7,11 +7,12 @@ import com.magistr.app.repository.*;
 import com.magistr.app.service.AcademicCalendarGridService;
 import com.magistr.app.service.AcademicStructureService;
 import com.magistr.app.service.ScheduleGeneratorService;
-import com.magistr.app.utils.AcademicCalendarTitleBuilder;
 import org.springframework.http.ResponseEntity;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.bind.annotation.*;

+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -25,11 +26,7 @@ import java.util.stream.Collectors;
 public class AcademicCalendarController {

    private final AcademicCalendarRepository calendarRepository;
-    private final AcademicCalendarDayRepository calendarDayRepository;
-    private final AcademicYearRepository academicYearRepository;
-    private final SpecialtiesRepository specialtiesRepository;
-    private final SpecialtyProfileRepository profileRepository;
-    private final EducationFormRepository educationFormRepository;
+    private final AcademicCalendarPeriodRepository calendarPeriodRepository;
    private final SubjectRepository subjectRepository;
    private final AcademicCalendarSubjectRepository calendarSubjectRepository;
    private final AcademicCalendarGridService calendarGridService;
@@ -37,22 +34,14 @@ public class AcademicCalendarController {
    private final AcademicStructureService academicStructureService;

    public AcademicCalendarController(AcademicCalendarRepository calendarRepository,
-                                      AcademicCalendarDayRepository calendarDayRepository,
-                                      AcademicYearRepository academicYearRepository,
-                                      SpecialtiesRepository specialtiesRepository,
-                                      SpecialtyProfileRepository profileRepository,
-                                      EducationFormRepository educationFormRepository,
+                                      AcademicCalendarPeriodRepository calendarPeriodRepository,
                                      SubjectRepository subjectRepository,
                                      AcademicCalendarSubjectRepository calendarSubjectRepository,
                                      AcademicCalendarGridService calendarGridService,
                                      ScheduleGeneratorService scheduleGeneratorService,
                                      AcademicStructureService academicStructureService) {
        this.calendarRepository = calendarRepository;
-        this.calendarDayRepository = calendarDayRepository;
-        this.academicYearRepository = academicYearRepository;
-        this.specialtiesRepository = specialtiesRepository;
-        this.profileRepository = profileRepository;
-        this.educationFormRepository = educationFormRepository;
+        this.calendarPeriodRepository = calendarPeriodRepository;
        this.subjectRepository = subjectRepository;
        this.calendarSubjectRepository = calendarSubjectRepository;
        this.calendarGridService = calendarGridService;
@@ -79,10 +68,7 @@ public class AcademicCalendarController {
    @PostMapping
    public ResponseEntity<?> createCalendar(@RequestBody AcademicCalendarDto request) {
        try {
-            AcademicCalendar calendar = new AcademicCalendar();
-            applyCalendar(calendar, request);
-            scheduleGeneratorService.clearCache();
-            return ResponseEntity.ok(toCalendarDto(calendarRepository.save(calendar)));
+            return ResponseEntity.ok(toCalendarDto(academicStructureService.createCalendar(request)));
        } catch (IllegalArgumentException e) {
            return ResponseEntity.badRequest().body(Map.of("message", e.getMessage()));
        }
@@ -108,8 +94,10 @@ public class AcademicCalendarController {
        if (!calendarRepository.existsById(id)) {
            return ResponseEntity.notFound().build();
        }
-        return ResponseEntity.ok(calendarDayRepository.findByCalendarIdWithActivity(id).stream()
-                .map(this::toGridDayDto)
+        return ResponseEntity.ok(calendarPeriodRepository.findByCalendarIdWithActivity(id).stream()
+                .flatMap(period -> period.getStartDate()
+                        .datesUntil(period.getEndDate().plusDays(1))
+                        .map(date -> toGridDayDto(period, date)))
                .toList());
    }

@@ -149,41 +137,6 @@ public class AcademicCalendarController {
        }
    }

-    private void applyCalendar(AcademicCalendar calendar, AcademicCalendarDto request) {
-        if (request == null) {
-            throw new IllegalArgumentException("Передайте данные календарного графика");
-        }
-        if (request.courseCount() == null || request.courseCount() <= 0) {
-            throw new IllegalArgumentException("Количество курсов должно быть больше нуля");
-        }
-        if (request.courseCount() > 8) {
-            throw new IllegalArgumentException("Количество курсов не может быть больше 8");
-        }
-        if (request.academicYearId() == null || request.specialtyId() == null
-                || request.specialtyProfileId() == null || request.studyFormId() == null) {
-            throw new IllegalArgumentException("Учебный год, специальность, профиль и форма обучения обязательны");
-        }
-
-        AcademicYear year = academicYearRepository.findById(request.academicYearId())
-                .orElseThrow(() -> new IllegalArgumentException("Учебный год не найден"));
-        Speciality speciality = specialtiesRepository.findById(request.specialtyId())
-                .orElseThrow(() -> new IllegalArgumentException("Специальность не найдена"));
-        SpecialtyProfile profile = profileRepository.findById(request.specialtyProfileId())
-                .orElseThrow(() -> new IllegalArgumentException("Профиль обучения не найден"));
-        if (!profile.getSpeciality().getId().equals(speciality.getId())) {
-            throw new IllegalArgumentException("Профиль не относится к выбранной специальности");
-        }
-        EducationForm studyForm = educationFormRepository.findById(request.studyFormId())
-                .orElseThrow(() -> new IllegalArgumentException("Форма обучения не найдена"));
-
-        calendar.setTitle(AcademicCalendarTitleBuilder.build(year, speciality, profile, studyForm));
-        calendar.setAcademicYear(year);
-        calendar.setSpeciality(speciality);
-        calendar.setSpecialtyProfile(profile);
-        calendar.setStudyForm(studyForm);
-        calendar.setCourseCount(request.courseCount());
-    }
-
    private void replaceCalendarSubjects(AcademicCalendar calendar, List<AcademicCalendarSubjectDto> rows) {
        if (rows.size() > 1000) {
            throw new IllegalArgumentException("Слишком много дисциплин для одного графика");
@@ -254,15 +207,19 @@ public class AcademicCalendarController {
        );
    }

-    private AcademicCalendarGridDayDto toGridDayDto(AcademicCalendarDay day) {
-        AcademicCalendarActivityType activityType = day.getActivityType();
+    private AcademicCalendarGridDayDto toGridDayDto(AcademicCalendarPeriod period, LocalDate date) {
+        AcademicCalendarActivityType activityType = period.getActivityType();
+        AcademicYear academicYear = period.getAcademicCalendar().getAcademicYear();
+        long daysFromYearStart = ChronoUnit.DAYS.between(academicYear.getStartDate(), date);
+        int daysBeforeYearStartInFirstWeek = academicYear.getStartDate().getDayOfWeek().getValue() - 1;
+        int weekNumber = Math.toIntExact((daysBeforeYearStartInFirstWeek + daysFromYearStart) / 7 + 1);
        return new AcademicCalendarGridDayDto(
-                day.getId(),
-                day.getAcademicCalendar().getId(),
-                day.getCourseNumber(),
-                day.getDate(),
-                day.getWeekNumber(),
-                day.getDayOfWeek(),
+                period.getId(),
+                period.getAcademicCalendar().getId(),
+                period.getCourseNumber(),
+                date,
+                weekNumber,
+                date.getDayOfWeek().getValue(),
                activityType.getId(),
                activityType.getCode(),
                activityType.getName(),
--- a/backend/src/main/java/com/magistr/app/controller/DatabaseConstraintViolationMapper.java
+++ b/backend/src/main/java/com/magistr/app/controller/DatabaseConstraintViolationMapper.java
@@ -34,9 +34,8 @@ final class DatabaseConstraintViolationMapper {
            badRequest("chk_semesters_type", "Недопустимый тип семестра"),
            badRequest("chk_semesters_dates", "Дата окончания семестра раньше даты начала"),
            badRequest("chk_academic_calendars_course_count", "Количество курсов должно быть от 1 до 8"),
-            badRequest("chk_calendar_days_course_positive", "Номер курса должен быть положительным"),
-            badRequest("chk_calendar_days_week_positive", "Номер недели должен быть положительным"),
-            badRequest("chk_calendar_days_day", "День недели должен быть от 1 до 7"),
+            badRequest("chk_calendar_periods_course_positive", "Номер курса должен быть положительным"),
+            badRequest("chk_calendar_periods_dates", "Дата окончания периода раньше даты начала"),
            badRequest("chk_academic_calendar_subjects_semester_positive", "Номер семестра должен быть положительным"),
            badRequest("chk_student_groups_group_size_positive", "Численность группы должна быть больше нуля"),
            badRequest("chk_student_groups_year_start_positive", "Год начала обучения должен быть больше нуля"),
@@ -61,8 +60,10 @@ final class DatabaseConstraintViolationMapper {
            conflict("uq_time_slot_scopes_weekday", "Сетка времени для этого дня недели уже существует"),
            conflict("uq_time_slots_scope_order", "Пара с таким номером уже существует в выбранной сетке"),
            conflict("uq_semesters_year_type", "Семестр такого типа уже существует в учебном году"),
+            conflict("uq_schedule_versions_number", "Версия с таким номером уже существует в семестре"),
+            conflict("uq_schedule_versions_published_semester", "Для семестра уже опубликована другая версия расписания"),
            conflict("uq_academic_calendar_title", "Календарный график с таким названием уже существует"),
-            conflict("uq_calendar_days", "День календарного графика уже существует"),
+            conflict("ex_calendar_periods_no_overlap", "Периоды активности одного курса пересекаются"),
            conflict("uq_academic_calendar_subject", "Дисциплина уже добавлена в этот семестр графика"),
            conflict("uq_group_calendar_year", "Группе уже назначен календарный график на учебный год"),
            conflict("uq_schedule_rule_slots_exact_payload", "Такой слот правила расписания уже существует"),
--- a/backend/src/main/java/com/magistr/app/controller/GlobalExceptionHandler.java
+++ b/backend/src/main/java/com/magistr/app/controller/GlobalExceptionHandler.java
@@ -11,6 +11,7 @@ import org.springframework.http.converter.HttpMessageNotReadableException;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
 import org.springframework.web.method.annotation.MethodArgumentTypeMismatchException;
+import org.springframework.web.server.ResponseStatusException;

 import java.time.Instant;
 import java.util.LinkedHashMap;
@@ -51,6 +52,19 @@ public class GlobalExceptionHandler {
        return error(HttpStatus.NOT_FOUND, message, request);
    }

+    @ExceptionHandler(ResponseStatusException.class)
+    public ResponseEntity<Map<String, Object>> handleResponseStatus(
+            ResponseStatusException exception,
+            HttpServletRequest request
+    ) {
+        HttpStatus status = HttpStatus.resolve(exception.getStatusCode().value());
+        HttpStatus resolvedStatus = status == null ? HttpStatus.INTERNAL_SERVER_ERROR : status;
+        String message = exception.getReason() == null || exception.getReason().isBlank()
+                ? "Операция недоступна"
+                : exception.getReason();
+        return error(resolvedStatus, message, request);
+    }
+
    @ExceptionHandler({
            HttpMessageNotReadableException.class,
            MethodArgumentTypeMismatchException.class
@@ -100,6 +114,8 @@ public class GlobalExceptionHandler {
            case BAD_REQUEST -> "Некорректный запрос";
            case CONFLICT -> "Конфликт";
            case NOT_FOUND -> "Не найдено";
+            case FORBIDDEN -> "Доступ запрещён";
+            case UNAUTHORIZED -> "Требуется вход";
            case INTERNAL_SERVER_ERROR -> "Внутренняя ошибка сервера";
            default -> status.name();
        };
--- a/backend/src/main/java/com/magistr/app/controller/ScheduleQualityController.java
+++ b/backend/src/main/java/com/magistr/app/controller/ScheduleQualityController.java
@@ -0,0 +1,44 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.config.auth.RequireRoles;
+import com.magistr.app.dto.ScheduleQualityAnalysisDto;
+import com.magistr.app.dto.ScheduleQualityRecommendationsDto;
+import com.magistr.app.model.Role;
+import com.magistr.app.service.ScheduleQualityService;
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.time.LocalDate;
+
+@RestController
+@RequestMapping("/api/edu-office/schedule/quality")
+@RequireRoles({Role.ADMIN, Role.EDUCATION_OFFICE})
+public class ScheduleQualityController {
+
+    private final ScheduleQualityService scheduleQualityService;
+
+    public ScheduleQualityController(ScheduleQualityService scheduleQualityService) {
+        this.scheduleQualityService = scheduleQualityService;
+    }
+
+    @GetMapping
+    public ScheduleQualityAnalysisDto analyze(
+            @RequestParam Long semesterId,
+            @RequestParam(name = "versionId", required = false) Long versionId
+    ) {
+        return scheduleQualityService.analyze(semesterId, versionId);
+    }
+
+    @GetMapping("/recommendations")
+    public ScheduleQualityRecommendationsDto recommendations(
+            @RequestParam Long semesterId,
+            @RequestParam(name = "versionId", required = false) Long versionId,
+            @RequestParam Long scheduleRuleSlotId,
+            @RequestParam @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate lessonDate
+    ) {
+        return scheduleQualityService.recommendations(semesterId, versionId, scheduleRuleSlotId, lessonDate);
+    }
+}
--- a/backend/src/main/java/com/magistr/app/controller/ScheduleRuleAdminController.java
+++ b/backend/src/main/java/com/magistr/app/controller/ScheduleRuleAdminController.java
@@ -34,8 +34,9 @@ public class ScheduleRuleAdminController {

    @GetMapping
    public List<ScheduleRuleDto> getAll(@RequestParam(name = "semesterId", required = false) Long semesterId,
-                                        @RequestParam(name = "groupId", required = false) Long groupId) {
-        return scheduleRuleService.getAll(semesterId, groupId);
+                                        @RequestParam(name = "groupId", required = false) Long groupId,
+                                        @RequestParam(name = "versionId", required = false) Long versionId) {
+        return scheduleRuleService.getAll(semesterId, groupId, versionId);
    }

    @GetMapping("/{id}")
@@ -46,6 +47,7 @@ public class ScheduleRuleAdminController {
    @PostMapping
    public ResponseEntity<?> create(@RequestBody ScheduleRuleDto request) {
        try {
+            requireScheduleVersion(request);
            return ResponseEntity.ok(scheduleRuleService.create(request));
        } catch (ScheduleRuleConflictException exception) {
            return conflictResponse(exception);
@@ -55,6 +57,7 @@ public class ScheduleRuleAdminController {
    @PutMapping("/{id}")
    public ResponseEntity<?> update(@PathVariable("id") Long id, @RequestBody ScheduleRuleDto request) {
        try {
+            requireScheduleVersion(request);
            return ResponseEntity.ok(scheduleRuleService.update(id, request));
        } catch (ScheduleRuleConflictException exception) {
            return conflictResponse(exception);
@@ -77,4 +80,10 @@ public class ScheduleRuleAdminController {
        body.put("conflictReasons", exception.getConflictReasons());
        return ResponseEntity.status(HttpStatus.CONFLICT).body(body);
    }
+
+    private void requireScheduleVersion(ScheduleRuleDto request) {
+        if (request == null || request.scheduleVersionId() == null) {
+            throw new IllegalArgumentException("Выберите версию расписания");
+        }
+    }
 }
--- a/backend/src/main/java/com/magistr/app/controller/ScheduleVersionController.java
+++ b/backend/src/main/java/com/magistr/app/controller/ScheduleVersionController.java
@@ -0,0 +1,82 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.config.auth.RequireRoles;
+import com.magistr.app.dto.ScheduleVersionActionDto;
+import com.magistr.app.dto.ScheduleVersionCreateDto;
+import com.magistr.app.dto.ScheduleVersionDiffDto;
+import com.magistr.app.dto.ScheduleVersionDto;
+import com.magistr.app.dto.ScheduleVersionHistoryDto;
+import com.magistr.app.dto.ScheduleVersionValidationDto;
+import com.magistr.app.model.Role;
+import com.magistr.app.service.ScheduleVersionService;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/edu-office/schedule/versions")
+@RequireRoles({Role.ADMIN, Role.EDUCATION_OFFICE})
+public class ScheduleVersionController {
+
+    private final ScheduleVersionService service;
+
+    public ScheduleVersionController(ScheduleVersionService service) {
+        this.service = service;
+    }
+
+    @GetMapping
+    public List<ScheduleVersionDto> getVersions(@RequestParam("semesterId") Long semesterId) {
+        return service.getVersions(semesterId);
+    }
+
+    @GetMapping("/{id}")
+    public ScheduleVersionDto getVersion(@PathVariable("id") Long id) {
+        return service.getVersion(id);
+    }
+
+    @PostMapping
+    public ResponseEntity<ScheduleVersionDto> createDraft(@RequestBody ScheduleVersionCreateDto request) {
+        return ResponseEntity.ok(service.createDraft(request));
+    }
+
+    @GetMapping("/{id}/validate")
+    public ScheduleVersionValidationDto validate(@PathVariable("id") Long id) {
+        return service.validate(id);
+    }
+
+    @GetMapping("/{id}/diff")
+    public ScheduleVersionDiffDto diff(
+            @PathVariable("id") Long id,
+            @RequestParam(name = "baseVersionId", required = false) Long baseVersionId
+    ) {
+        return service.diff(id, baseVersionId);
+    }
+
+    @PostMapping("/{id}/publish")
+    public ScheduleVersionDto publish(
+            @PathVariable("id") Long id,
+            @RequestBody ScheduleVersionActionDto request
+    ) {
+        return service.publish(id, request == null ? null : request.reason());
+    }
+
+    @PostMapping("/{id}/restore")
+    public ScheduleVersionDto restore(
+            @PathVariable("id") Long id,
+            @RequestBody ScheduleVersionActionDto request
+    ) {
+        return service.restore(id, request == null ? null : request.reason());
+    }
+
+    @GetMapping("/history")
+    public List<ScheduleVersionHistoryDto> history(@RequestParam("semesterId") Long semesterId) {
+        return service.getHistory(semesterId);
+    }
+}
--- a/backend/src/main/java/com/magistr/app/controller/TeacherAbsenceController.java
+++ b/backend/src/main/java/com/magistr/app/controller/TeacherAbsenceController.java
@@ -0,0 +1,68 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.config.auth.RequireRoles;
+import com.magistr.app.dto.TeacherAbsenceDto;
+import com.magistr.app.dto.TeacherAbsenceRequest;
+import com.magistr.app.dto.TeacherAbsenceResolutionRequest;
+import com.magistr.app.dto.TeacherAbsenceReviewRequest;
+import com.magistr.app.dto.TeacherAbsenceWizardDto;
+import com.magistr.app.model.Role;
+import com.magistr.app.service.TeacherAbsenceService;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/teacher-absences")
+@RequireRoles({Role.ADMIN, Role.EDUCATION_OFFICE, Role.DEPARTMENT, Role.TEACHER})
+public class TeacherAbsenceController {
+
+    private final TeacherAbsenceService absenceService;
+
+    public TeacherAbsenceController(TeacherAbsenceService absenceService) {
+        this.absenceService = absenceService;
+    }
+
+    @GetMapping
+    public List<TeacherAbsenceDto> getAll(@RequestParam(required = false) String status) {
+        return absenceService.getAll(status);
+    }
+
+    @PostMapping
+    public TeacherAbsenceDto create(@RequestBody TeacherAbsenceRequest request) {
+        return absenceService.create(request);
+    }
+
+    @PostMapping("/{id}/review")
+    public TeacherAbsenceDto review(
+            @PathVariable Long id,
+            @RequestBody TeacherAbsenceReviewRequest request
+    ) {
+        return absenceService.review(id, request);
+    }
+
+    @GetMapping("/{id}/wizard")
+    public TeacherAbsenceWizardDto getWizard(@PathVariable Long id) {
+        return absenceService.getWizard(id);
+    }
+
+    @PostMapping("/{id}/resolve")
+    public TeacherAbsenceWizardDto resolve(
+            @PathVariable Long id,
+            @RequestBody TeacherAbsenceResolutionRequest request
+    ) {
+        return absenceService.resolve(id, request);
+    }
+
+    @DeleteMapping("/{id}")
+    public TeacherAbsenceDto cancel(@PathVariable Long id) {
+        return absenceService.cancel(id);
+    }
+}
--- a/backend/src/main/java/com/magistr/app/controller/TeacherChangeRequestController.java
+++ b/backend/src/main/java/com/magistr/app/controller/TeacherChangeRequestController.java
@@ -0,0 +1,64 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.config.auth.RequireRoles;
+import com.magistr.app.dto.TeacherChangeCandidatesDto;
+import com.magistr.app.dto.TeacherChangeRequestDto;
+import com.magistr.app.dto.TeacherChangeRequestPayload;
+import com.magistr.app.dto.TeacherChangeReviewRequest;
+import com.magistr.app.model.Role;
+import com.magistr.app.service.TeacherChangeRequestService;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.time.LocalDate;
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/teacher-change-requests")
+@RequireRoles({Role.ADMIN, Role.EDUCATION_OFFICE, Role.DEPARTMENT, Role.TEACHER})
+public class TeacherChangeRequestController {
+
+    private final TeacherChangeRequestService requestService;
+
+    public TeacherChangeRequestController(TeacherChangeRequestService requestService) {
+        this.requestService = requestService;
+    }
+
+    @GetMapping
+    public List<TeacherChangeRequestDto> getAll(@RequestParam(required = false) String status) {
+        return requestService.getAll(status);
+    }
+
+    @GetMapping("/candidates")
+    public TeacherChangeCandidatesDto getCandidates(
+            @RequestParam Long baseRuleSlotId,
+            @RequestParam LocalDate lessonDate,
+            @RequestParam(required = false) LocalDate targetDate
+    ) {
+        return requestService.getCandidates(baseRuleSlotId, lessonDate, targetDate);
+    }
+
+    @PostMapping
+    public TeacherChangeRequestDto create(@RequestBody TeacherChangeRequestPayload request) {
+        return requestService.create(request);
+    }
+
+    @PostMapping("/{id}/review")
+    public TeacherChangeRequestDto review(
+            @PathVariable Long id,
+            @RequestBody TeacherChangeReviewRequest request
+    ) {
+        return requestService.review(id, request);
+    }
+
+    @DeleteMapping("/{id}")
+    public TeacherChangeRequestDto cancel(@PathVariable Long id) {
+        return requestService.cancel(id);
+    }
+}
--- a/backend/src/main/java/com/magistr/app/controller/TeacherPreferenceController.java
+++ b/backend/src/main/java/com/magistr/app/controller/TeacherPreferenceController.java
@@ -0,0 +1,62 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.config.auth.RequireRoles;
+import com.magistr.app.dto.TeacherPreferenceDto;
+import com.magistr.app.dto.TeacherPreferenceMetaDto;
+import com.magistr.app.dto.TeacherPreferenceRequest;
+import com.magistr.app.dto.TeacherPreferenceReviewRequest;
+import com.magistr.app.model.Role;
+import com.magistr.app.service.TeacherPreferenceService;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/teacher-preferences")
+@RequireRoles({Role.ADMIN, Role.EDUCATION_OFFICE, Role.DEPARTMENT, Role.TEACHER})
+public class TeacherPreferenceController {
+
+    private final TeacherPreferenceService preferenceService;
+
+    public TeacherPreferenceController(TeacherPreferenceService preferenceService) {
+        this.preferenceService = preferenceService;
+    }
+
+    @GetMapping("/meta")
+    public TeacherPreferenceMetaDto getMeta() {
+        return preferenceService.getMeta();
+    }
+
+    @GetMapping
+    public List<TeacherPreferenceDto> getAll(
+            @RequestParam(required = false) Long semesterId,
+            @RequestParam(required = false) String status
+    ) {
+        return preferenceService.getAll(semesterId, status);
+    }
+
+    @PostMapping
+    public TeacherPreferenceDto create(@RequestBody TeacherPreferenceRequest request) {
+        return preferenceService.create(request);
+    }
+
+    @PostMapping("/{id}/review")
+    public TeacherPreferenceDto review(
+            @PathVariable Long id,
+            @RequestBody TeacherPreferenceReviewRequest request
+    ) {
+        return preferenceService.review(id, request);
+    }
+
+    @DeleteMapping("/{id}")
+    public TeacherPreferenceDto cancel(@PathVariable Long id) {
+        return preferenceService.cancel(id);
+    }
+}
--- a/backend/src/main/java/com/magistr/app/controller/WorkloadController.java
+++ b/backend/src/main/java/com/magistr/app/controller/WorkloadController.java
@@ -53,7 +53,7 @@ public class WorkloadController {
        List<RenderedLessonDto> lessons = scheduleQueryService.searchForAggregation(
                effectiveDepartmentId, null, startDate, endDate
        );
-        return summarizeTeacherWorkload(lessons, startDate, endDate);
+        return summarizeTeacherWorkload(lessons, startDate, endDate, effectiveDepartmentId);
    }

    @GetMapping("/classrooms")
@@ -98,15 +98,19 @@ public class WorkloadController {

    private List<WorkloadSummaryDto> summarizeTeacherWorkload(List<RenderedLessonDto> lessons,
                                                              LocalDate startDate,
-                                                              LocalDate endDate) {
-        Map<Long, List<TeacherDepartmentAssignment>> assignmentsByTeacher =
-                assignmentsByTeacher(lessons, startDate, endDate);
+                                                              LocalDate endDate,
+                                                              Long scopedDepartmentId) {
+        Map<Long, List<TeacherDepartmentAssignment>> assignmentsByTeacher = scopedDepartmentId == null
+                ? assignmentsByTeacher(lessons, startDate, endDate)
+                : Map.of();
        Map<TeacherDepartmentKey, List<RenderedLessonDto>> grouped = lessons.stream()
                .filter(lesson -> lesson.teacherId() != null)
                .collect(Collectors.groupingBy(
                        lesson -> new TeacherDepartmentKey(
                                lesson.teacherId(),
-                                departmentIdAtLesson(lesson, assignmentsByTeacher).orElse(null)
+                                scopedDepartmentId != null
+                                        ? scopedDepartmentId
+                                        : departmentIdAtLesson(lesson, assignmentsByTeacher).orElse(null)
                        ),
                        LinkedHashMap::new,
                        Collectors.toList()
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleQualityAnalysisDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleQualityAnalysisDto.java
@@ -0,0 +1,56 @@
+package com.magistr.app.dto;
+
+import java.time.LocalDate;
+import java.util.List;
+import com.magistr.app.model.ScheduleVersionStatus;
+
+public record ScheduleQualityAnalysisDto(
+        Long semesterId,
+        String semesterLabel,
+        LocalDate startDate,
+        LocalDate endDate,
+        int score,
+        int rawPenalty,
+        int lessonCount,
+        int totalProblemCount,
+        boolean problemsTruncated,
+        List<Metric> metrics,
+        List<Problem> problems,
+        Long scheduleVersionId,
+        Integer scheduleVersionNumber,
+        String scheduleVersionName,
+        ScheduleVersionStatus scheduleVersionStatus
+) {
+    public record Metric(
+            String code,
+            String label,
+            double value,
+            String unit,
+            int penalty,
+            String explanation
+    ) {
+    }
+
+    public record Problem(
+            String id,
+            String type,
+            String severity,
+            String title,
+            String description,
+            int penalty,
+            Long scheduleRuleId,
+            int affectedLessonCount,
+            List<String> problemTypes,
+            List<String> issueLabels,
+            Long scheduleRuleSlotId,
+            LocalDate lessonDate,
+            Integer timeSlotOrder,
+            String subjectName,
+            Long entityId,
+            String entityName,
+            Integer requiredCapacity,
+            Integer classroomCapacity,
+            boolean optimizable
+    ) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleQualityRecommendationsDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleQualityRecommendationsDto.java
@@ -0,0 +1,26 @@
+package com.magistr.app.dto;
+
+import java.time.LocalDate;
+import java.util.List;
+
+public record ScheduleQualityRecommendationsDto(
+        Long scheduleRuleSlotId,
+        LocalDate lessonDate,
+        String subjectName,
+        int baselineScore,
+        List<Candidate> candidates
+) {
+    public record Candidate(
+            String id,
+            String action,
+            String label,
+            String description,
+            int scoreDelta,
+            int penaltyDelta,
+            int resultingScore,
+            List<String> improvements,
+            List<String> tradeoffs,
+            ScheduleOverrideDto override
+    ) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleRuleDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleRuleDto.java
@@ -19,6 +19,7 @@ public record ScheduleRuleDto(
        Integer practiceStartWeek,
        List<Long> groupIds,
        List<String> groupNames,
-        List<ScheduleRuleSlotDto> slots
+        List<ScheduleRuleSlotDto> slots,
+        Long scheduleVersionId
 ) {
 }
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleVersionActionDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleVersionActionDto.java
@@ -0,0 +1,4 @@
+package com.magistr.app.dto;
+
+public record ScheduleVersionActionDto(String reason) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleVersionCreateDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleVersionCreateDto.java
@@ -0,0 +1,8 @@
+package com.magistr.app.dto;
+
+public record ScheduleVersionCreateDto(
+        Long semesterId,
+        String name,
+        Long basedOnVersionId
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleVersionDiffDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleVersionDiffDto.java
@@ -0,0 +1,30 @@
+package com.magistr.app.dto;
+
+import java.util.List;
+
+public record ScheduleVersionDiffDto(
+        Long baseVersionId,
+        String baseVersionLabel,
+        Long targetVersionId,
+        String targetVersionLabel,
+        int addedRuleCount,
+        int removedRuleCount,
+        int changedRuleCount,
+        int unchangedRuleCount,
+        int addedLessonCount,
+        int removedLessonCount,
+        int changedLessonCount,
+        List<RuleChange> ruleChanges
+) {
+    public record RuleChange(
+            String type,
+            Long versionGroupId,
+            Long beforeRuleId,
+            Long afterRuleId,
+            String subjectName,
+            List<String> groupNames,
+            String beforeSummary,
+            String afterSummary
+    ) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleVersionDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleVersionDto.java
@@ -0,0 +1,27 @@
+package com.magistr.app.dto;
+
+import com.magistr.app.model.ScheduleVersionStatus;
+
+import java.time.Instant;
+
+public record ScheduleVersionDto(
+        Long id,
+        Long semesterId,
+        String semesterLabel,
+        Integer versionNumber,
+        String name,
+        ScheduleVersionStatus status,
+        Long basedOnVersionId,
+        Long restoredFromVersionId,
+        String changeReason,
+        Long createdById,
+        String createdByName,
+        Instant createdAt,
+        Long publishedById,
+        String publishedByName,
+        Instant publishedAt,
+        Instant archivedAt,
+        long ruleCount,
+        long slotCount
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleVersionHistoryDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleVersionHistoryDto.java
@@ -0,0 +1,16 @@
+package com.magistr.app.dto;
+
+import java.time.Instant;
+
+public record ScheduleVersionHistoryDto(
+        Long id,
+        Long versionId,
+        Integer versionNumber,
+        String versionName,
+        String action,
+        Long actorId,
+        String actorName,
+        String reason,
+        Instant createdAt
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/ScheduleVersionValidationDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/ScheduleVersionValidationDto.java
@@ -0,0 +1,12 @@
+package com.magistr.app.dto;
+
+import java.util.List;
+
+public record ScheduleVersionValidationDto(
+        Long versionId,
+        boolean valid,
+        long ruleCount,
+        long slotCount,
+        List<String> issues
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceDto.java
@@ -0,0 +1,23 @@
+package com.magistr.app.dto;
+
+import java.time.Instant;
+import java.time.LocalDate;
+
+public record TeacherAbsenceDto(
+        Long id,
+        Long teacherId,
+        String teacherName,
+        Long teacherDepartmentId,
+        LocalDate startDate,
+        LocalDate endDate,
+        String reason,
+        String status,
+        Long requestedBy,
+        Long reviewedBy,
+        String reviewComment,
+        Instant reviewedAt,
+        Instant createdAt,
+        Instant updatedAt,
+        long decisionCount
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceRequest.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceRequest.java
@@ -0,0 +1,11 @@
+package com.magistr.app.dto;
+
+import java.time.LocalDate;
+
+public record TeacherAbsenceRequest(
+        Long teacherId,
+        LocalDate startDate,
+        LocalDate endDate,
+        String reason
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceResolutionRequest.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceResolutionRequest.java
@@ -0,0 +1,20 @@
+package com.magistr.app.dto;
+
+import java.time.LocalDate;
+import java.util.List;
+
+public record TeacherAbsenceResolutionRequest(
+        List<Decision> decisions
+) {
+    public record Decision(
+            Long baseRuleSlotId,
+            LocalDate lessonDate,
+            String resolution,
+            LocalDate targetLessonDate,
+            Long newTimeSlotId,
+            Long newClassroomId,
+            Long newTeacherId,
+            String comment
+    ) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceReviewRequest.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceReviewRequest.java
@@ -0,0 +1,7 @@
+package com.magistr.app.dto;
+
+public record TeacherAbsenceReviewRequest(
+        Boolean approved,
+        String comment
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceWizardDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherAbsenceWizardDto.java
@@ -0,0 +1,59 @@
+package com.magistr.app.dto;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.List;
+
+public record TeacherAbsenceWizardDto(
+        TeacherAbsenceDto absence,
+        List<AffectedLesson> lessons,
+        List<DecisionLog> journal
+) {
+    public record Candidate(Long id, String name, String description) {
+    }
+
+    public record MoveCandidate(
+            LocalDate targetDate,
+            Long timeSlotId,
+            Integer orderNumber,
+            LocalTime startTime,
+            LocalTime endTime,
+            String description
+    ) {
+    }
+
+    public record AffectedLesson(
+            Long baseRuleSlotId,
+            LocalDate lessonDate,
+            LocalTime startTime,
+            LocalTime endTime,
+            Long subjectId,
+            String subjectName,
+            Long lessonTypeId,
+            String lessonTypeName,
+            Long classroomId,
+            String classroomName,
+            List<String> groupNames,
+            Long existingOverrideId,
+            String decisionStatus,
+            List<Candidate> teacherCandidates,
+            List<MoveCandidate> moveCandidates,
+            List<Candidate> classroomCandidates,
+            boolean cancellationAvailable
+    ) {
+    }
+
+    public record DecisionLog(
+            Long id,
+            Long baseRuleSlotId,
+            LocalDate lessonDate,
+            String resolution,
+            String status,
+            Long scheduleOverrideId,
+            String comment,
+            Long decidedBy,
+            Instant decidedAt
+    ) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherChangeCandidatesDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherChangeCandidatesDto.java
@@ -0,0 +1,23 @@
+package com.magistr.app.dto;
+
+import java.time.LocalDate;
+import java.util.List;
+
+public record TeacherChangeCandidatesDto(
+        RenderedLessonDto lesson,
+        Long semesterId,
+        LocalDate semesterStartDate,
+        LocalDate semesterEndDate,
+        List<LocalDate> availableDates,
+        LocalDate checkedDate,
+        List<CandidateOption> timeSlots,
+        List<CandidateOption> classrooms
+) {
+    public record CandidateOption(
+            Long id,
+            String label,
+            boolean available,
+            String conflictMessage
+    ) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherChangeRequestDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherChangeRequestDto.java
@@ -0,0 +1,50 @@
+package com.magistr.app.dto;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.List;
+
+public record TeacherChangeRequestDto(
+        Long id,
+        Long teacherId,
+        String teacherName,
+        Long departmentId,
+        Long baseRuleSlotId,
+        LocalDate lessonDate,
+        String subjectName,
+        String lessonTypeName,
+        List<String> groupNames,
+        Long sourceTimeSlotId,
+        Integer sourceTimeSlotOrder,
+        LocalTime sourceStartTime,
+        LocalTime sourceEndTime,
+        Long sourceClassroomId,
+        String sourceClassroomName,
+        String requestType,
+        LocalDate targetLessonDate,
+        Long requestedTimeSlotId,
+        Integer requestedTimeSlotOrder,
+        LocalTime requestedStartTime,
+        LocalTime requestedEndTime,
+        Long requestedClassroomId,
+        String requestedClassroomName,
+        String reason,
+        String status,
+        Long reviewedBy,
+        String reviewComment,
+        Instant reviewedAt,
+        Long appliedOverrideId,
+        Instant createdAt,
+        Instant updatedAt,
+        List<HistoryItem> history
+) {
+    public record HistoryItem(
+            Long id,
+            String status,
+            String comment,
+            Long actorId,
+            Instant createdAt
+    ) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherChangeRequestPayload.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherChangeRequestPayload.java
@@ -0,0 +1,14 @@
+package com.magistr.app.dto;
+
+import java.time.LocalDate;
+
+public record TeacherChangeRequestPayload(
+        Long baseRuleSlotId,
+        LocalDate lessonDate,
+        String requestType,
+        LocalDate targetLessonDate,
+        Long requestedTimeSlotId,
+        Long requestedClassroomId,
+        String reason
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherChangeReviewRequest.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherChangeReviewRequest.java
@@ -0,0 +1,4 @@
+package com.magistr.app.dto;
+
+public record TeacherChangeReviewRequest(Boolean approved, String comment) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherPreferenceDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherPreferenceDto.java
@@ -0,0 +1,34 @@
+package com.magistr.app.dto;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalTime;
+
+public record TeacherPreferenceDto(
+        Long id,
+        Long teacherId,
+        String teacherName,
+        Long departmentId,
+        Long semesterId,
+        String academicYearTitle,
+        String semesterType,
+        LocalDate semesterStartDate,
+        LocalDate semesterEndDate,
+        String preferenceType,
+        Integer dayOfWeek,
+        String dayName,
+        Long timeSlotId,
+        Integer timeSlotOrder,
+        LocalTime startTime,
+        LocalTime endTime,
+        LocalDate preferenceDate,
+        String comment,
+        String status,
+        Long requestedBy,
+        Long reviewedBy,
+        String reviewComment,
+        Instant reviewedAt,
+        Instant createdAt,
+        Instant updatedAt
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherPreferenceMetaDto.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherPreferenceMetaDto.java
@@ -0,0 +1,9 @@
+package com.magistr.app.dto;
+
+import java.util.List;
+
+public record TeacherPreferenceMetaDto(
+        List<SemesterDto> semesters,
+        List<TimeSlotDto> timeSlots
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherPreferenceRequest.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherPreferenceRequest.java
@@ -0,0 +1,14 @@
+package com.magistr.app.dto;
+
+import java.time.LocalDate;
+
+public record TeacherPreferenceRequest(
+        Long teacherId,
+        Long semesterId,
+        String preferenceType,
+        Integer dayOfWeek,
+        Long timeSlotId,
+        LocalDate preferenceDate,
+        String comment
+) {
+}
--- a/backend/src/main/java/com/magistr/app/dto/TeacherPreferenceReviewRequest.java
+++ b/backend/src/main/java/com/magistr/app/dto/TeacherPreferenceReviewRequest.java
@@ -0,0 +1,4 @@
+package com.magistr.app.dto;
+
+public record TeacherPreferenceReviewRequest(Boolean approved, String comment) {
+}
--- a/backend/src/main/java/com/magistr/app/model/AcademicCalendarPeriod.java
+++ b/backend/src/main/java/com/magistr/app/model/AcademicCalendarPeriod.java
@@ -5,8 +5,8 @@ import jakarta.persistence.*;
 import java.time.LocalDate;

@Entity
-@Table(name = "academic_calendar_days")
-public class AcademicCalendarDay {
+@Table(name = "academic_calendar_periods")
+public class AcademicCalendarPeriod {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
@@ -19,14 +19,11 @@ public class AcademicCalendarDay {
    @Column(name = "course_number", nullable = false)
    private Integer courseNumber;

-    @Column(nullable = false)
-    private LocalDate date;
+    @Column(name = "start_date", nullable = false)
+    private LocalDate startDate;

-    @Column(name = "week_number", nullable = false)
-    private Integer weekNumber;
-
-    @Column(name = "day_of_week", nullable = false)
-    private Integer dayOfWeek;
+    @Column(name = "end_date", nullable = false)
+    private LocalDate endDate;

    @ManyToOne(optional = false)
    @JoinColumn(name = "activity_type_id", nullable = false)
@@ -56,28 +53,20 @@ public class AcademicCalendarDay {
        this.courseNumber = courseNumber;
    }

-    public LocalDate getDate() {
-        return date;
+    public LocalDate getStartDate() {
+        return startDate;
    }

-    public void setDate(LocalDate date) {
-        this.date = date;
+    public void setStartDate(LocalDate startDate) {
+        this.startDate = startDate;
    }

-    public Integer getWeekNumber() {
-        return weekNumber;
+    public LocalDate getEndDate() {
+        return endDate;
    }

-    public void setWeekNumber(Integer weekNumber) {
-        this.weekNumber = weekNumber;
-    }
-
-    public Integer getDayOfWeek() {
-        return dayOfWeek;
-    }
-
-    public void setDayOfWeek(Integer dayOfWeek) {
-        this.dayOfWeek = dayOfWeek;
+    public void setEndDate(LocalDate endDate) {
+        this.endDate = endDate;
    }

    public AcademicCalendarActivityType getActivityType() {
--- a/backend/src/main/java/com/magistr/app/model/ScheduleRule.java
+++ b/backend/src/main/java/com/magistr/app/model/ScheduleRule.java
@@ -4,6 +4,7 @@ import com.fasterxml.jackson.annotation.JsonIgnore;
 import jakarta.persistence.*;

 import java.time.LocalDate;
+import java.time.Instant;
 import java.util.HashSet;
 import java.util.Set;

@@ -23,6 +24,23 @@ public class ScheduleRule {
    @JoinColumn(name = "semester_id", nullable = false)
    private Semester semester;

+    @ManyToOne(optional = false)
+    @JoinColumn(name = "schedule_version_id", nullable = false)
+    private ScheduleVersion scheduleVersion;
+
+    @Column(name = "version_group_id")
+    private Long versionGroupId;
+
+    @Column(name = "change_reason")
+    private String changeReason;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "created_by")
+    private User createdBy;
+
+    @Column(name = "created_at", nullable = false, insertable = false, updatable = false)
+    private Instant createdAt;
+
    @Column(nullable = false, length = 20)
    private String status = LifecycleEntity.STATUS_ACTIVE;

@@ -85,6 +103,42 @@ public class ScheduleRule {
        this.semester = semester;
    }

+    public ScheduleVersion getScheduleVersion() {
+        return scheduleVersion;
+    }
+
+    public void setScheduleVersion(ScheduleVersion scheduleVersion) {
+        this.scheduleVersion = scheduleVersion;
+    }
+
+    public Long getVersionGroupId() {
+        return versionGroupId;
+    }
+
+    public void setVersionGroupId(Long versionGroupId) {
+        this.versionGroupId = versionGroupId;
+    }
+
+    public String getChangeReason() {
+        return changeReason;
+    }
+
+    public void setChangeReason(String changeReason) {
+        this.changeReason = changeReason;
+    }
+
+    public User getCreatedBy() {
+        return createdBy;
+    }
+
+    public void setCreatedBy(User createdBy) {
+        this.createdBy = createdBy;
+    }
+
+    public Instant getCreatedAt() {
+        return createdAt;
+    }
+
    public String getStatus() {
        return status;
    }
--- a/backend/src/main/java/com/magistr/app/model/ScheduleVersion.java
+++ b/backend/src/main/java/com/magistr/app/model/ScheduleVersion.java
@@ -0,0 +1,166 @@
+package com.magistr.app.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+import java.time.Instant;
+
+@Entity
+@Table(name = "schedule_versions")
+public class ScheduleVersion {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false, fetch = FetchType.LAZY)
+    @JoinColumn(name = "semester_id", nullable = false)
+    private Semester semester;
+
+    @Column(name = "version_number", nullable = false)
+    private Integer versionNumber;
+
+    @Column(nullable = false, length = 160)
+    private String name;
+
+    @Enumerated(EnumType.STRING)
+    @Column(nullable = false, length = 20)
+    private ScheduleVersionStatus status = ScheduleVersionStatus.DRAFT;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "based_on_version_id")
+    private ScheduleVersion basedOnVersion;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "restored_from_version_id")
+    private ScheduleVersion restoredFromVersion;
+
+    @Column(name = "change_reason")
+    private String changeReason;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "created_by")
+    private User createdBy;
+
+    @Column(name = "created_at", nullable = false, insertable = false, updatable = false)
+    private Instant createdAt;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "published_by")
+    private User publishedBy;
+
+    @Column(name = "published_at")
+    private Instant publishedAt;
+
+    @Column(name = "archived_at")
+    private Instant archivedAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Semester getSemester() {
+        return semester;
+    }
+
+    public void setSemester(Semester semester) {
+        this.semester = semester;
+    }
+
+    public Integer getVersionNumber() {
+        return versionNumber;
+    }
+
+    public void setVersionNumber(Integer versionNumber) {
+        this.versionNumber = versionNumber;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public ScheduleVersionStatus getStatus() {
+        return status;
+    }
+
+    public void setStatus(ScheduleVersionStatus status) {
+        this.status = status;
+    }
+
+    public ScheduleVersion getBasedOnVersion() {
+        return basedOnVersion;
+    }
+
+    public void setBasedOnVersion(ScheduleVersion basedOnVersion) {
+        this.basedOnVersion = basedOnVersion;
+    }
+
+    public ScheduleVersion getRestoredFromVersion() {
+        return restoredFromVersion;
+    }
+
+    public void setRestoredFromVersion(ScheduleVersion restoredFromVersion) {
+        this.restoredFromVersion = restoredFromVersion;
+    }
+
+    public String getChangeReason() {
+        return changeReason;
+    }
+
+    public void setChangeReason(String changeReason) {
+        this.changeReason = changeReason;
+    }
+
+    public User getCreatedBy() {
+        return createdBy;
+    }
+
+    public void setCreatedBy(User createdBy) {
+        this.createdBy = createdBy;
+    }
+
+    public Instant getCreatedAt() {
+        return createdAt;
+    }
+
+    public User getPublishedBy() {
+        return publishedBy;
+    }
+
+    public void setPublishedBy(User publishedBy) {
+        this.publishedBy = publishedBy;
+    }
+
+    public Instant getPublishedAt() {
+        return publishedAt;
+    }
+
+    public void setPublishedAt(Instant publishedAt) {
+        this.publishedAt = publishedAt;
+    }
+
+    public Instant getArchivedAt() {
+        return archivedAt;
+    }
+
+    public void setArchivedAt(Instant archivedAt) {
+        this.archivedAt = archivedAt;
+    }
+}
--- a/backend/src/main/java/com/magistr/app/model/ScheduleVersionHistory.java
+++ b/backend/src/main/java/com/magistr/app/model/ScheduleVersionHistory.java
@@ -0,0 +1,79 @@
+package com.magistr.app.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+import java.time.Instant;
+
+@Entity
+@Table(name = "schedule_version_history")
+public class ScheduleVersionHistory {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false, fetch = FetchType.LAZY)
+    @JoinColumn(name = "version_id", nullable = false)
+    private ScheduleVersion version;
+
+    @Column(nullable = false, length = 30)
+    private String action;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "actor_id")
+    private User actor;
+
+    @Column
+    private String reason;
+
+    @Column(name = "created_at", nullable = false, insertable = false, updatable = false)
+    private Instant createdAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public ScheduleVersion getVersion() {
+        return version;
+    }
+
+    public void setVersion(ScheduleVersion version) {
+        this.version = version;
+    }
+
+    public String getAction() {
+        return action;
+    }
+
+    public void setAction(String action) {
+        this.action = action;
+    }
+
+    public User getActor() {
+        return actor;
+    }
+
+    public void setActor(User actor) {
+        this.actor = actor;
+    }
+
+    public String getReason() {
+        return reason;
+    }
+
+    public void setReason(String reason) {
+        this.reason = reason;
+    }
+
+    public Instant getCreatedAt() {
+        return createdAt;
+    }
+}
--- a/backend/src/main/java/com/magistr/app/model/ScheduleVersionStatus.java
+++ b/backend/src/main/java/com/magistr/app/model/ScheduleVersionStatus.java
@@ -0,0 +1,7 @@
+package com.magistr.app.model;
+
+public enum ScheduleVersionStatus {
+    DRAFT,
+    PUBLISHED,
+    ARCHIVED
+}
--- a/backend/src/main/java/com/magistr/app/model/TeacherAbsence.java
+++ b/backend/src/main/java/com/magistr/app/model/TeacherAbsence.java
@@ -0,0 +1,141 @@
+package com.magistr.app.model;
+
+import jakarta.persistence.*;
+
+import java.time.Instant;
+import java.time.LocalDate;
+
+@Entity
+@Table(name = "teacher_absences")
+public class TeacherAbsence {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "teacher_id", nullable = false)
+    private User teacher;
+
+    @Column(name = "start_date", nullable = false)
+    private LocalDate startDate;
+
+    @Column(name = "end_date", nullable = false)
+    private LocalDate endDate;
+
+    @Column(nullable = false, columnDefinition = "TEXT")
+    private String reason;
+
+    @Column(nullable = false, length = 20)
+    private String status;
+
+    @Column(name = "requested_by")
+    private Long requestedBy;
+
+    @Column(name = "reviewed_by")
+    private Long reviewedBy;
+
+    @Column(name = "review_comment", columnDefinition = "TEXT")
+    private String reviewComment;
+
+    @Column(name = "reviewed_at")
+    private Instant reviewedAt;
+
+    @Column(name = "created_at", nullable = false)
+    private Instant createdAt;
+
+    @Column(name = "updated_at", nullable = false)
+    private Instant updatedAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public User getTeacher() {
+        return teacher;
+    }
+
+    public void setTeacher(User teacher) {
+        this.teacher = teacher;
+    }
+
+    public LocalDate getStartDate() {
+        return startDate;
+    }
+
+    public void setStartDate(LocalDate startDate) {
+        this.startDate = startDate;
+    }
+
+    public LocalDate getEndDate() {
+        return endDate;
+    }
+
+    public void setEndDate(LocalDate endDate) {
+        this.endDate = endDate;
+    }
+
+    public String getReason() {
+        return reason;
+    }
+
+    public void setReason(String reason) {
+        this.reason = reason;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public Long getRequestedBy() {
+        return requestedBy;
+    }
+
+    public void setRequestedBy(Long requestedBy) {
+        this.requestedBy = requestedBy;
+    }
+
+    public Long getReviewedBy() {
+        return reviewedBy;
+    }
+
+    public void setReviewedBy(Long reviewedBy) {
+        this.reviewedBy = reviewedBy;
+    }
+
+    public String getReviewComment() {
+        return reviewComment;
+    }
+
+    public void setReviewComment(String reviewComment) {
+        this.reviewComment = reviewComment;
+    }
+
+    public Instant getReviewedAt() {
+        return reviewedAt;
+    }
+
+    public void setReviewedAt(Instant reviewedAt) {
+        this.reviewedAt = reviewedAt;
+    }
+
+    public Instant getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(Instant createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public Instant getUpdatedAt() {
+        return updatedAt;
+    }
+
+    public void setUpdatedAt(Instant updatedAt) {
+        this.updatedAt = updatedAt;
+    }
+}
--- a/backend/src/main/java/com/magistr/app/model/TeacherAbsenceDecision.java
+++ b/backend/src/main/java/com/magistr/app/model/TeacherAbsenceDecision.java
@@ -0,0 +1,121 @@
+package com.magistr.app.model;
+
+import jakarta.persistence.*;
+
+import java.time.Instant;
+import java.time.LocalDate;
+
+@Entity
+@Table(name = "teacher_absence_decisions")
+public class TeacherAbsenceDecision {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "absence_id", nullable = false)
+    private TeacherAbsence absence;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "base_rule_slot_id", nullable = false)
+    private ScheduleRuleSlot baseRuleSlot;
+
+    @Column(name = "lesson_date", nullable = false)
+    private LocalDate lessonDate;
+
+    @Column(nullable = false, length = 30)
+    private String resolution;
+
+    @Column(name = "decision_status", nullable = false, length = 20)
+    private String decisionStatus;
+
+    @ManyToOne
+    @JoinColumn(name = "schedule_override_id")
+    private ScheduleOverride scheduleOverride;
+
+    @Column(columnDefinition = "TEXT")
+    private String comment;
+
+    @Column(name = "decided_by")
+    private Long decidedBy;
+
+    @Column(name = "decided_at", nullable = false)
+    private Instant decidedAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public TeacherAbsence getAbsence() {
+        return absence;
+    }
+
+    public void setAbsence(TeacherAbsence absence) {
+        this.absence = absence;
+    }
+
+    public ScheduleRuleSlot getBaseRuleSlot() {
+        return baseRuleSlot;
+    }
+
+    public void setBaseRuleSlot(ScheduleRuleSlot baseRuleSlot) {
+        this.baseRuleSlot = baseRuleSlot;
+    }
+
+    public LocalDate getLessonDate() {
+        return lessonDate;
+    }
+
+    public void setLessonDate(LocalDate lessonDate) {
+        this.lessonDate = lessonDate;
+    }
+
+    public String getResolution() {
+        return resolution;
+    }
+
+    public void setResolution(String resolution) {
+        this.resolution = resolution;
+    }
+
+    public String getDecisionStatus() {
+        return decisionStatus;
+    }
+
+    public void setDecisionStatus(String decisionStatus) {
+        this.decisionStatus = decisionStatus;
+    }
+
+    public ScheduleOverride getScheduleOverride() {
+        return scheduleOverride;
+    }
+
+    public void setScheduleOverride(ScheduleOverride scheduleOverride) {
+        this.scheduleOverride = scheduleOverride;
+    }
+
+    public String getComment() {
+        return comment;
+    }
+
+    public void setComment(String comment) {
+        this.comment = comment;
+    }
+
+    public Long getDecidedBy() {
+        return decidedBy;
+    }
+
+    public void setDecidedBy(Long decidedBy) {
+        this.decidedBy = decidedBy;
+    }
+
+    public Instant getDecidedAt() {
+        return decidedAt;
+    }
+
+    public void setDecidedAt(Instant decidedAt) {
+        this.decidedAt = decidedAt;
+    }
+}
--- a/backend/src/main/java/com/magistr/app/model/TeacherChangeRequest.java
+++ b/backend/src/main/java/com/magistr/app/model/TeacherChangeRequest.java
@@ -0,0 +1,104 @@
+package com.magistr.app.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+import java.time.Instant;
+import java.time.LocalDate;
+
+@Entity
+@Table(name = "teacher_change_requests")
+public class TeacherChangeRequest {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "teacher_id", nullable = false)
+    private User teacher;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "base_rule_slot_id", nullable = false)
+    private ScheduleRuleSlot baseRuleSlot;
+
+    @Column(name = "lesson_date", nullable = false)
+    private LocalDate lessonDate;
+
+    @Column(name = "request_type", nullable = false, length = 30)
+    private String requestType;
+
+    @Column(name = "target_lesson_date")
+    private LocalDate targetLessonDate;
+
+    @ManyToOne
+    @JoinColumn(name = "requested_time_slot_id")
+    private TimeSlot requestedTimeSlot;
+
+    @ManyToOne
+    @JoinColumn(name = "requested_classroom_id")
+    private Classroom requestedClassroom;
+
+    @Column(nullable = false, columnDefinition = "TEXT")
+    private String reason;
+
+    @Column(nullable = false, length = 20)
+    private String status;
+
+    @Column(name = "reviewed_by")
+    private Long reviewedBy;
+
+    @Column(name = "review_comment", columnDefinition = "TEXT")
+    private String reviewComment;
+
+    @Column(name = "reviewed_at")
+    private Instant reviewedAt;
+
+    @ManyToOne
+    @JoinColumn(name = "applied_override_id")
+    private ScheduleOverride appliedOverride;
+
+    @Column(name = "created_at", nullable = false)
+    private Instant createdAt;
+
+    @Column(name = "updated_at", nullable = false)
+    private Instant updatedAt;
+
+    public Long getId() { return id; }
+    public User getTeacher() { return teacher; }
+    public void setTeacher(User teacher) { this.teacher = teacher; }
+    public ScheduleRuleSlot getBaseRuleSlot() { return baseRuleSlot; }
+    public void setBaseRuleSlot(ScheduleRuleSlot baseRuleSlot) { this.baseRuleSlot = baseRuleSlot; }
+    public LocalDate getLessonDate() { return lessonDate; }
+    public void setLessonDate(LocalDate lessonDate) { this.lessonDate = lessonDate; }
+    public String getRequestType() { return requestType; }
+    public void setRequestType(String requestType) { this.requestType = requestType; }
+    public LocalDate getTargetLessonDate() { return targetLessonDate; }
+    public void setTargetLessonDate(LocalDate targetLessonDate) { this.targetLessonDate = targetLessonDate; }
+    public TimeSlot getRequestedTimeSlot() { return requestedTimeSlot; }
+    public void setRequestedTimeSlot(TimeSlot requestedTimeSlot) { this.requestedTimeSlot = requestedTimeSlot; }
+    public Classroom getRequestedClassroom() { return requestedClassroom; }
+    public void setRequestedClassroom(Classroom requestedClassroom) { this.requestedClassroom = requestedClassroom; }
+    public String getReason() { return reason; }
+    public void setReason(String reason) { this.reason = reason; }
+    public String getStatus() { return status; }
+    public void setStatus(String status) { this.status = status; }
+    public Long getReviewedBy() { return reviewedBy; }
+    public void setReviewedBy(Long reviewedBy) { this.reviewedBy = reviewedBy; }
+    public String getReviewComment() { return reviewComment; }
+    public void setReviewComment(String reviewComment) { this.reviewComment = reviewComment; }
+    public Instant getReviewedAt() { return reviewedAt; }
+    public void setReviewedAt(Instant reviewedAt) { this.reviewedAt = reviewedAt; }
+    public ScheduleOverride getAppliedOverride() { return appliedOverride; }
+    public void setAppliedOverride(ScheduleOverride appliedOverride) { this.appliedOverride = appliedOverride; }
+    public Instant getCreatedAt() { return createdAt; }
+    public void setCreatedAt(Instant createdAt) { this.createdAt = createdAt; }
+    public Instant getUpdatedAt() { return updatedAt; }
+    public void setUpdatedAt(Instant updatedAt) { this.updatedAt = updatedAt; }
+}
--- a/backend/src/main/java/com/magistr/app/model/TeacherChangeRequestHistory.java
+++ b/backend/src/main/java/com/magistr/app/model/TeacherChangeRequestHistory.java
@@ -0,0 +1,49 @@
+package com.magistr.app.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+import java.time.Instant;
+
+@Entity
+@Table(name = "teacher_change_request_history")
+public class TeacherChangeRequestHistory {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "request_id", nullable = false)
+    private TeacherChangeRequest request;
+
+    @Column(nullable = false, length = 20)
+    private String status;
+
+    @Column(columnDefinition = "TEXT")
+    private String comment;
+
+    @Column(name = "actor_id")
+    private Long actorId;
+
+    @Column(name = "created_at", nullable = false)
+    private Instant createdAt;
+
+    public Long getId() { return id; }
+    public TeacherChangeRequest getRequest() { return request; }
+    public void setRequest(TeacherChangeRequest request) { this.request = request; }
+    public String getStatus() { return status; }
+    public void setStatus(String status) { this.status = status; }
+    public String getComment() { return comment; }
+    public void setComment(String comment) { this.comment = comment; }
+    public Long getActorId() { return actorId; }
+    public void setActorId(Long actorId) { this.actorId = actorId; }
+    public Instant getCreatedAt() { return createdAt; }
+    public void setCreatedAt(Instant createdAt) { this.createdAt = createdAt; }
+}
--- a/backend/src/main/java/com/magistr/app/model/TeacherPreference.java
+++ b/backend/src/main/java/com/magistr/app/model/TeacherPreference.java
@@ -0,0 +1,97 @@
+package com.magistr.app.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+import java.time.Instant;
+import java.time.LocalDate;
+
+@Entity
+@Table(name = "teacher_preferences")
+public class TeacherPreference {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "teacher_id", nullable = false)
+    private User teacher;
+
+    @ManyToOne(optional = false)
+    @JoinColumn(name = "semester_id", nullable = false)
+    private Semester semester;
+
+    @Column(name = "preference_type", nullable = false, length = 30)
+    private String preferenceType;
+
+    @Column(name = "day_of_week")
+    private Integer dayOfWeek;
+
+    @ManyToOne
+    @JoinColumn(name = "time_slot_id")
+    private TimeSlot timeSlot;
+
+    @Column(name = "preference_date")
+    private LocalDate preferenceDate;
+
+    @Column(columnDefinition = "TEXT")
+    private String comment;
+
+    @Column(nullable = false, length = 20)
+    private String status;
+
+    @Column(name = "requested_by")
+    private Long requestedBy;
+
+    @Column(name = "reviewed_by")
+    private Long reviewedBy;
+
+    @Column(name = "review_comment", columnDefinition = "TEXT")
+    private String reviewComment;
+
+    @Column(name = "reviewed_at")
+    private Instant reviewedAt;
+
+    @Column(name = "created_at", nullable = false)
+    private Instant createdAt;
+
+    @Column(name = "updated_at", nullable = false)
+    private Instant updatedAt;
+
+    public Long getId() { return id; }
+    public User getTeacher() { return teacher; }
+    public void setTeacher(User teacher) { this.teacher = teacher; }
+    public Semester getSemester() { return semester; }
+    public void setSemester(Semester semester) { this.semester = semester; }
+    public String getPreferenceType() { return preferenceType; }
+    public void setPreferenceType(String preferenceType) { this.preferenceType = preferenceType; }
+    public Integer getDayOfWeek() { return dayOfWeek; }
+    public void setDayOfWeek(Integer dayOfWeek) { this.dayOfWeek = dayOfWeek; }
+    public TimeSlot getTimeSlot() { return timeSlot; }
+    public void setTimeSlot(TimeSlot timeSlot) { this.timeSlot = timeSlot; }
+    public LocalDate getPreferenceDate() { return preferenceDate; }
+    public void setPreferenceDate(LocalDate preferenceDate) { this.preferenceDate = preferenceDate; }
+    public String getComment() { return comment; }
+    public void setComment(String comment) { this.comment = comment; }
+    public String getStatus() { return status; }
+    public void setStatus(String status) { this.status = status; }
+    public Long getRequestedBy() { return requestedBy; }
+    public void setRequestedBy(Long requestedBy) { this.requestedBy = requestedBy; }
+    public Long getReviewedBy() { return reviewedBy; }
+    public void setReviewedBy(Long reviewedBy) { this.reviewedBy = reviewedBy; }
+    public String getReviewComment() { return reviewComment; }
+    public void setReviewComment(String reviewComment) { this.reviewComment = reviewComment; }
+    public Instant getReviewedAt() { return reviewedAt; }
+    public void setReviewedAt(Instant reviewedAt) { this.reviewedAt = reviewedAt; }
+    public Instant getCreatedAt() { return createdAt; }
+    public void setCreatedAt(Instant createdAt) { this.createdAt = createdAt; }
+    public Instant getUpdatedAt() { return updatedAt; }
+    public void setUpdatedAt(Instant updatedAt) { this.updatedAt = updatedAt; }
+}
--- a/backend/src/main/java/com/magistr/app/repository/AcademicCalendarDayRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/AcademicCalendarDayRepository.java
@@ -1,71 +0,0 @@
-package com.magistr.app.repository;
-
-import com.magistr.app.model.AcademicCalendarDay;
-import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.data.jpa.repository.Modifying;
-import org.springframework.data.jpa.repository.Query;
-import org.springframework.data.repository.query.Param;
-
-import java.time.LocalDate;
-import java.util.Collection;
-import java.util.List;
-import java.util.Optional;
-
-public interface AcademicCalendarDayRepository extends JpaRepository<AcademicCalendarDay, Long> {
-
-    @Query("""
-            select day
-            from AcademicCalendarDay day
-            join fetch day.activityType
-            where day.academicCalendar.id = :calendarId
-            order by day.courseNumber asc, day.date asc
-            """)
-    List<AcademicCalendarDay> findByCalendarIdWithActivity(@Param("calendarId") Long calendarId);
-
-    @Query("""
-            select day
-            from AcademicCalendarDay day
-            join fetch day.activityType
-            where day.academicCalendar.id = :calendarId
-              and day.courseNumber = :courseNumber
-              and day.date = :date
-            """)
-    Optional<AcademicCalendarDay> findByCalendarIdAndCourseNumberAndDate(
-            @Param("calendarId") Long calendarId,
-            @Param("courseNumber") Integer courseNumber,
-            @Param("date") LocalDate date
-    );
-
-    @Query("""
-            select day
-            from AcademicCalendarDay day
-            join fetch day.academicCalendar
-            join fetch day.activityType
-            where day.academicCalendar.id in :calendarIds
-              and day.date between :startDate and :endDate
-            order by day.academicCalendar.id, day.courseNumber, day.date
-            """)
-    List<AcademicCalendarDay> findForScheduleBatch(
-            @Param("calendarIds") Collection<Long> calendarIds,
-            @Param("startDate") LocalDate startDate,
-            @Param("endDate") LocalDate endDate
-    );
-
-    boolean existsByActivityTypeId(Long activityTypeId);
-
-    boolean existsByAcademicCalendarIdAndCourseNumberGreaterThan(Long calendarId, Integer courseNumber);
-
-    @Query("""
-            select case when count(day) > 0 then true else false end
-            from AcademicCalendarDay day
-            where day.academicCalendar.id = :calendarId
-              and (day.date < :startDate or day.date > :endDate)
-            """)
-    boolean existsOutsideDateRange(@Param("calendarId") Long calendarId,
-                                   @Param("startDate") LocalDate startDate,
-                                   @Param("endDate") LocalDate endDate);
-
-    @Modifying
-    @Query("delete from AcademicCalendarDay day where day.academicCalendar.id = :calendarId")
-    void deleteByCalendarId(@Param("calendarId") Long calendarId);
-}
--- a/backend/src/main/java/com/magistr/app/repository/AcademicCalendarPeriodRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/AcademicCalendarPeriodRepository.java
@@ -0,0 +1,77 @@
+package com.magistr.app.repository;
+
+import com.magistr.app.model.AcademicCalendarPeriod;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.time.LocalDate;
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+
+public interface AcademicCalendarPeriodRepository extends JpaRepository<AcademicCalendarPeriod, Long> {
+
+    @Query("""
+            select period
+            from AcademicCalendarPeriod period
+            join fetch period.academicCalendar calendar
+            join fetch calendar.academicYear
+            join fetch period.activityType
+            where period.academicCalendar.id = :calendarId
+            order by period.courseNumber asc, period.startDate asc
+            """)
+    List<AcademicCalendarPeriod> findByCalendarIdWithActivity(@Param("calendarId") Long calendarId);
+
+    @Query("""
+            select period
+            from AcademicCalendarPeriod period
+            join fetch period.activityType
+            where period.academicCalendar.id = :calendarId
+              and period.courseNumber = :courseNumber
+              and period.startDate <= :date
+              and period.endDate >= :date
+            """)
+    Optional<AcademicCalendarPeriod> findByCalendarIdAndCourseNumberAndDate(
+            @Param("calendarId") Long calendarId,
+            @Param("courseNumber") Integer courseNumber,
+            @Param("date") LocalDate date
+    );
+
+    @Query("""
+            select period
+            from AcademicCalendarPeriod period
+            join fetch period.academicCalendar
+            join fetch period.activityType
+            where period.academicCalendar.id in :calendarIds
+              and period.courseNumber = :courseNumber
+              and period.endDate >= :startDate
+              and period.startDate <= :endDate
+            order by period.academicCalendar.id, period.startDate
+            """)
+    List<AcademicCalendarPeriod> findForScheduleBatch(
+            @Param("calendarIds") Collection<Long> calendarIds,
+            @Param("courseNumber") Integer courseNumber,
+            @Param("startDate") LocalDate startDate,
+            @Param("endDate") LocalDate endDate
+    );
+
+    boolean existsByActivityTypeId(Long activityTypeId);
+
+    boolean existsByAcademicCalendarIdAndCourseNumberGreaterThan(Long calendarId, Integer courseNumber);
+
+    @Query("""
+            select case when count(period) > 0 then true else false end
+            from AcademicCalendarPeriod period
+            where period.academicCalendar.id = :calendarId
+              and (period.startDate < :startDate or period.endDate > :endDate)
+            """)
+    boolean existsOutsideDateRange(@Param("calendarId") Long calendarId,
+                                   @Param("startDate") LocalDate startDate,
+                                   @Param("endDate") LocalDate endDate);
+
+    @Modifying
+    @Query("delete from AcademicCalendarPeriod period where period.academicCalendar.id = :calendarId")
+    void deleteByCalendarId(@Param("calendarId") Long calendarId);
+}
--- a/backend/src/main/java/com/magistr/app/repository/ScheduleOverrideRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/ScheduleOverrideRepository.java
@@ -19,12 +19,14 @@ public interface ScheduleOverrideRepository extends JpaRepository<ScheduleOverri
            from ScheduleOverride o
            left join fetch o.baseRuleSlot baseSlot
            left join fetch baseSlot.scheduleRule rule
+            join rule.scheduleVersion version
            left join fetch rule.semester
            left join fetch o.newTimeSlot
            left join fetch o.newClassroom
            left join fetch o.newTeacher
-            where o.lessonDate between :startDate and :endDate
-               or o.targetLessonDate between :startDate and :endDate
+            where (o.lessonDate between :startDate and :endDate
+               or o.targetLessonDate between :startDate and :endDate)
+              and version.status = 'PUBLISHED'
            """)
    List<ScheduleOverride> findByLessonDateBetweenWithDetails(
            @Param("startDate") LocalDate startDate,
@@ -38,6 +40,7 @@ public interface ScheduleOverrideRepository extends JpaRepository<ScheduleOverri
            from ScheduleOverride o
            join fetch o.baseRuleSlot baseSlot
            join fetch baseSlot.scheduleRule rule
+            join fetch rule.scheduleVersion version
            join fetch rule.subject
            left join fetch rule.groups
            join fetch rule.semester
@@ -48,6 +51,7 @@ public interface ScheduleOverrideRepository extends JpaRepository<ScheduleOverri
            left join fetch o.newTimeSlot
            left join fetch o.newClassroom
            left join fetch o.newTeacher
+            where version.status = 'PUBLISHED'
            order by o.lessonDate, o.id
            """)
    List<ScheduleOverride> findAllWithRegistryDetails();
@@ -57,6 +61,7 @@ public interface ScheduleOverrideRepository extends JpaRepository<ScheduleOverri
            from ScheduleOverride o
            join fetch o.baseRuleSlot baseSlot
            join fetch baseSlot.scheduleRule rule
+            join fetch rule.scheduleVersion version
            join fetch rule.subject
            left join fetch rule.groups
            join fetch rule.semester
@@ -67,8 +72,9 @@ public interface ScheduleOverrideRepository extends JpaRepository<ScheduleOverri
            left join fetch o.newTimeSlot
            left join fetch o.newClassroom
            left join fetch o.newTeacher
-            where o.lessonDate between :startDate and :endDate
-               or o.targetLessonDate between :startDate and :endDate
+            where (o.lessonDate between :startDate and :endDate
+               or o.targetLessonDate between :startDate and :endDate)
+              and version.status = 'PUBLISHED'
            order by o.lessonDate, o.id
            """)
    List<ScheduleOverride> findForRegistry(
@@ -81,12 +87,14 @@ public interface ScheduleOverrideRepository extends JpaRepository<ScheduleOverri
            from ScheduleOverride o
            left join fetch o.baseRuleSlot baseSlot
            left join fetch baseSlot.scheduleRule rule
+            join rule.scheduleVersion version
            left join fetch rule.semester
            left join fetch o.newTimeSlot
            left join fetch o.newClassroom
            left join fetch o.newTeacher
-            where o.lessonDate in :dates
-               or o.targetLessonDate in :dates
+            where (o.lessonDate in :dates
+               or o.targetLessonDate in :dates)
+              and version.status = 'PUBLISHED'
            """)
    List<ScheduleOverride> findAffectingDatesWithDetails(@Param("dates") Collection<LocalDate> dates);

--- a/backend/src/main/java/com/magistr/app/repository/ScheduleRuleRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/ScheduleRuleRepository.java
@@ -17,9 +17,11 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            select distinct r
            from ScheduleRule r
            join r.groups g
+            join r.scheduleVersion version
            left join fetch r.subject
            left join fetch r.semester sem
            left join fetch sem.academicYear
+            left join fetch r.scheduleVersion
            left join fetch r.groups groups
            left join fetch r.slots slots
            left join fetch slots.timeSlot
@@ -30,6 +32,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            left join fetch slots.lessonType
            where g.id = :groupId
              and sem.id = :semesterId
+              and version.status = 'PUBLISHED'
              and r.status <> 'ARCHIVED'
            """)
    List<ScheduleRule> findByGroupIdAndSemesterId(
@@ -41,6 +44,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            select distinct r
            from ScheduleRule r
            join r.slots teacherSlot
+            join r.scheduleVersion version
            left join fetch r.subject
            left join fetch r.semester sem
            left join fetch sem.academicYear
@@ -54,6 +58,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            left join fetch slots.lessonType
            where teacherSlot.teacher.id = :teacherId
              and sem.id = :semesterId
+              and version.status = 'PUBLISHED'
              and r.status <> 'ARCHIVED'
            """)
    List<ScheduleRule> findByTeacherIdAndSemesterId(
@@ -65,6 +70,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            select distinct r
            from ScheduleRule r
            join r.groups matchingGroup
+            join r.scheduleVersion version
            left join fetch r.subject
            left join fetch r.semester sem
            left join fetch sem.academicYear
@@ -78,6 +84,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            left join fetch slots.lessonType
            where matchingGroup.id in :groupIds
              and sem.id in :semesterIds
+              and version.status = 'PUBLISHED'
              and r.status <> 'ARCHIVED'
            """)
    List<ScheduleRule> findByGroupIdsAndSemesterIds(
@@ -89,6 +96,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            select distinct r
            from ScheduleRule r
            join r.slots teacherSlot
+            join r.scheduleVersion version
            left join fetch r.subject
            left join fetch r.semester sem
            left join fetch sem.academicYear
@@ -102,6 +110,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            left join fetch slots.lessonType
            where teacherSlot.teacher.id = :teacherId
              and sem.id in :semesterIds
+              and version.status = 'PUBLISHED'
              and r.status <> 'ARCHIVED'
            """)
    List<ScheduleRule> findByTeacherIdAndSemesterIds(
@@ -112,6 +121,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
    @Query("""
            select distinct r
            from ScheduleRule r
+            join r.scheduleVersion version
            left join fetch r.subject
            left join fetch r.semester sem
            left join fetch sem.academicYear
@@ -124,6 +134,7 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            left join fetch slots.classroom
            left join fetch slots.lessonType
            where r.status <> 'ARCHIVED'
+              and version.status = 'PUBLISHED'
            order by r.id desc
            """)
    List<ScheduleRule> findAllWithDetails();
@@ -156,12 +167,38 @@ public interface ScheduleRuleRepository extends JpaRepository<ScheduleRule, Long
            @Param("excludeRuleId") Long excludeRuleId
    );

+    @Query("""
+            select distinct rule
+            from ScheduleRule rule
+            left join fetch rule.subject
+            left join fetch rule.semester semester
+            left join fetch semester.academicYear
+            left join fetch rule.scheduleVersion version
+            left join fetch rule.groups groups
+            left join fetch rule.slots slots
+            left join fetch slots.timeSlot
+            left join fetch slots.subgroups slotSubgroups
+            left join fetch slotSubgroups.studentGroup
+            left join fetch slots.teacher
+            left join fetch slots.classroom
+            left join fetch slots.lessonType
+            where version.id = :versionId
+              and rule.status <> 'ARCHIVED'
+              and (:excludeRuleId is null or rule.id <> :excludeRuleId)
+            order by rule.id
+            """)
+    List<ScheduleRule> findActiveByVersionIdWithDetails(
+            @Param("versionId") Long versionId,
+            @Param("excludeRuleId") Long excludeRuleId
+    );
+
    @Query("""
            select distinct r
            from ScheduleRule r
            left join fetch r.subject
            left join fetch r.semester sem
            left join fetch sem.academicYear
+            left join fetch r.scheduleVersion
            left join fetch r.groups groups
            left join fetch r.slots slots
            left join fetch slots.timeSlot
--- a/backend/src/main/java/com/magistr/app/repository/ScheduleRuleSlotRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/ScheduleRuleSlotRepository.java
@@ -5,10 +5,23 @@ import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;

+import java.util.Collection;
+
 public interface ScheduleRuleSlotRepository extends JpaRepository<ScheduleRuleSlot, Long> {

    @Query("select case when count(slot) > 0 then true else false end from ScheduleRuleSlot slot join slot.subgroups subgroup where subgroup.id = :subgroupId")
    boolean existsBySubgroupId(@Param("subgroupId") Long subgroupId);

    boolean existsByTimeSlotId(Long timeSlotId);
+
+    @Query(value = """
+            SELECT EXISTS (
+                SELECT 1 FROM schedule_overrides WHERE base_rule_slot_id IN (:slotIds)
+                UNION ALL
+                SELECT 1 FROM teacher_change_requests WHERE base_rule_slot_id IN (:slotIds)
+                UNION ALL
+                SELECT 1 FROM teacher_absence_decisions WHERE base_rule_slot_id IN (:slotIds)
+            )
+            """, nativeQuery = true)
+    boolean hasProtectedReferences(@Param("slotIds") Collection<Long> slotIds);
 }
--- a/backend/src/main/java/com/magistr/app/repository/ScheduleVersionHistoryRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/ScheduleVersionHistoryRepository.java
@@ -0,0 +1,21 @@
+package com.magistr.app.repository;
+
+import com.magistr.app.model.ScheduleVersionHistory;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.List;
+
+public interface ScheduleVersionHistoryRepository extends JpaRepository<ScheduleVersionHistory, Long> {
+
+    @Query("""
+            select history
+            from ScheduleVersionHistory history
+            left join fetch history.version version
+            left join fetch history.actor
+            where version.semester.id = :semesterId
+            order by history.createdAt desc, history.id desc
+            """)
+    List<ScheduleVersionHistory> findBySemesterIdWithDetails(@Param("semesterId") Long semesterId);
+}
--- a/backend/src/main/java/com/magistr/app/repository/ScheduleVersionRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/ScheduleVersionRepository.java
@@ -0,0 +1,55 @@
+package com.magistr.app.repository;
+
+import com.magistr.app.model.ScheduleVersion;
+import com.magistr.app.model.ScheduleVersionStatus;
+import jakarta.persistence.LockModeType;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface ScheduleVersionRepository extends JpaRepository<ScheduleVersion, Long> {
+
+    @Query("""
+            select version
+            from ScheduleVersion version
+            left join fetch version.semester semester
+            left join fetch semester.academicYear
+            left join fetch version.createdBy
+            left join fetch version.publishedBy
+            left join fetch version.basedOnVersion
+            left join fetch version.restoredFromVersion
+            where semester.id = :semesterId
+            order by version.versionNumber desc
+            """)
+    List<ScheduleVersion> findBySemesterIdWithDetails(@Param("semesterId") Long semesterId);
+
+    @Query("""
+            select version
+            from ScheduleVersion version
+            left join fetch version.semester semester
+            left join fetch semester.academicYear
+            left join fetch version.createdBy
+            left join fetch version.publishedBy
+            left join fetch version.basedOnVersion
+            left join fetch version.restoredFromVersion
+            where version.id = :id
+            """)
+    Optional<ScheduleVersion> findByIdWithDetails(@Param("id") Long id);
+
+    Optional<ScheduleVersion> findFirstBySemesterIdAndStatus(Long semesterId, ScheduleVersionStatus status);
+
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("select version from ScheduleVersion version where version.id = :id")
+    Optional<ScheduleVersion> findByIdForUpdate(@Param("id") Long id);
+
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("select version from ScheduleVersion version where version.semester.id = :semesterId order by version.id")
+    List<ScheduleVersion> findBySemesterIdForUpdate(@Param("semesterId") Long semesterId);
+
+    @Query("select coalesce(max(version.versionNumber), 0) from ScheduleVersion version where version.semester.id = :semesterId")
+    int findMaxVersionNumber(@Param("semesterId") Long semesterId);
+}
--- a/backend/src/main/java/com/magistr/app/repository/TeacherAbsenceDecisionRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/TeacherAbsenceDecisionRepository.java
@@ -0,0 +1,24 @@
+package com.magistr.app.repository;
+
+import com.magistr.app.model.TeacherAbsenceDecision;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.List;
+
+public interface TeacherAbsenceDecisionRepository extends JpaRepository<TeacherAbsenceDecision, Long> {
+
+    long countByAbsenceId(Long absenceId);
+
+    @Query("""
+            select decision
+            from TeacherAbsenceDecision decision
+            join fetch decision.baseRuleSlot baseSlot
+            left join fetch decision.scheduleOverride
+            where decision.absence.id = :absenceId
+            order by decision.lessonDate, decision.id
+            """)
+    List<TeacherAbsenceDecision> findByAbsenceIdWithDetails(@Param("absenceId") Long absenceId);
+
+}
--- a/backend/src/main/java/com/magistr/app/repository/TeacherAbsenceRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/TeacherAbsenceRepository.java
@@ -0,0 +1,66 @@
+package com.magistr.app.repository;
+
+import com.magistr.app.model.TeacherAbsence;
+import jakarta.persistence.LockModeType;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.time.LocalDate;
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+
+public interface TeacherAbsenceRepository extends JpaRepository<TeacherAbsence, Long> {
+
+    @Query("""
+            select absence
+            from TeacherAbsence absence
+            join fetch absence.teacher
+            order by absence.startDate desc, absence.id desc
+            """)
+    List<TeacherAbsence> findAllWithTeacher();
+
+    @Query("""
+            select absence
+            from TeacherAbsence absence
+            join fetch absence.teacher
+            where absence.id = :id
+            """)
+    Optional<TeacherAbsence> findByIdWithTeacher(@Param("id") Long id);
+
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("""
+            select absence
+            from TeacherAbsence absence
+            join fetch absence.teacher
+            where absence.id = :id
+            """)
+    Optional<TeacherAbsence> findByIdForUpdate(@Param("id") Long id);
+
+    @Query("""
+            select count(absence) > 0
+            from TeacherAbsence absence
+            where absence.teacher.id = :teacherId
+              and absence.status in :statuses
+              and absence.startDate <= :endDate
+              and absence.endDate >= :startDate
+            """)
+    boolean existsOverlapping(
+            @Param("teacherId") Long teacherId,
+            @Param("statuses") Collection<String> statuses,
+            @Param("startDate") LocalDate startDate,
+            @Param("endDate") LocalDate endDate
+    );
+
+    @Query("""
+            select count(absence) > 0
+            from TeacherAbsence absence
+            where absence.teacher.id = :teacherId
+              and absence.status in ('APPROVED', 'RESOLVED')
+              and absence.startDate <= :date
+              and absence.endDate >= :date
+            """)
+    boolean isTeacherAbsentOn(@Param("teacherId") Long teacherId, @Param("date") LocalDate date);
+}
--- a/backend/src/main/java/com/magistr/app/repository/TeacherChangeRequestHistoryRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/TeacherChangeRequestHistoryRepository.java
@@ -0,0 +1,10 @@
+package com.magistr.app.repository;
+
+import com.magistr.app.model.TeacherChangeRequestHistory;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+
+public interface TeacherChangeRequestHistoryRepository extends JpaRepository<TeacherChangeRequestHistory, Long> {
+    List<TeacherChangeRequestHistory> findByRequestIdOrderByCreatedAtAscIdAsc(Long requestId);
+}
--- a/backend/src/main/java/com/magistr/app/repository/TeacherChangeRequestRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/TeacherChangeRequestRepository.java
@@ -0,0 +1,54 @@
+package com.magistr.app.repository;
+
+import com.magistr.app.model.TeacherChangeRequest;
+import jakarta.persistence.LockModeType;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Optional;
+
+public interface TeacherChangeRequestRepository extends JpaRepository<TeacherChangeRequest, Long> {
+
+    @Query("""
+            select request
+            from TeacherChangeRequest request
+            join fetch request.teacher
+            join fetch request.baseRuleSlot slot
+            join fetch slot.scheduleRule rule
+            join fetch rule.subject
+            join fetch slot.timeSlot
+            join fetch slot.classroom
+            left join fetch request.requestedTimeSlot
+            left join fetch request.requestedClassroom
+            left join fetch request.appliedOverride
+            order by request.createdAt desc, request.id desc
+            """)
+    List<TeacherChangeRequest> findAllWithDetails();
+
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("""
+            select request
+            from TeacherChangeRequest request
+            join fetch request.teacher
+            join fetch request.baseRuleSlot slot
+            join fetch slot.scheduleRule rule
+            join fetch rule.subject
+            join fetch slot.timeSlot
+            join fetch slot.classroom
+            left join fetch request.requestedTimeSlot
+            left join fetch request.requestedClassroom
+            left join fetch request.appliedOverride
+            where request.id = :id
+            """)
+    Optional<TeacherChangeRequest> findByIdForUpdate(@Param("id") Long id);
+
+    boolean existsByBaseRuleSlotIdAndLessonDateAndStatus(
+            Long baseRuleSlotId,
+            LocalDate lessonDate,
+            String status
+    );
+}
--- a/backend/src/main/java/com/magistr/app/repository/TeacherPreferenceRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/TeacherPreferenceRepository.java
@@ -0,0 +1,104 @@
+package com.magistr.app.repository;
+
+import com.magistr.app.model.TeacherPreference;
+import jakarta.persistence.LockModeType;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.time.LocalDate;
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+
+public interface TeacherPreferenceRepository extends JpaRepository<TeacherPreference, Long> {
+
+    @Query("""
+            select preference
+            from TeacherPreference preference
+            join fetch preference.teacher
+            join fetch preference.semester semester
+            join fetch semester.academicYear
+            left join fetch preference.timeSlot slot
+            left join fetch slot.timeSlotScope
+            order by preference.createdAt desc, preference.id desc
+            """)
+    List<TeacherPreference> findAllWithDetails();
+
+    @Query("""
+            select preference
+            from TeacherPreference preference
+            join fetch preference.teacher
+            join fetch preference.semester semester
+            join fetch semester.academicYear
+            left join fetch preference.timeSlot slot
+            left join fetch slot.timeSlotScope
+            where preference.id = :id
+            """)
+    Optional<TeacherPreference> findByIdWithDetails(@Param("id") Long id);
+
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("""
+            select preference
+            from TeacherPreference preference
+            join fetch preference.teacher
+            join fetch preference.semester semester
+            join fetch semester.academicYear
+            left join fetch preference.timeSlot slot
+            left join fetch slot.timeSlotScope
+            where preference.id = :id
+            """)
+    Optional<TeacherPreference> findByIdForUpdate(@Param("id") Long id);
+
+    @Query("""
+            select preference
+            from TeacherPreference preference
+            join fetch preference.teacher
+            join fetch preference.semester semester
+            left join fetch preference.timeSlot slot
+            where preference.teacher.id = :teacherId
+              and preference.semester.id = :semesterId
+              and preference.status = 'APPROVED'
+            order by preference.preferenceType, preference.preferenceDate, preference.dayOfWeek, slot.orderNumber
+            """)
+    List<TeacherPreference> findApprovedForTeacherAndSemester(
+            @Param("teacherId") Long teacherId,
+            @Param("semesterId") Long semesterId
+    );
+
+    @Query("""
+            select preference
+            from TeacherPreference preference
+            join fetch preference.teacher
+            join fetch preference.semester
+            left join fetch preference.timeSlot slot
+            left join fetch slot.timeSlotScope
+            where preference.semester.id = :semesterId
+              and preference.status = 'APPROVED'
+            order by preference.teacher.id, preference.preferenceType,
+                     preference.preferenceDate, preference.dayOfWeek, slot.orderNumber
+            """)
+    List<TeacherPreference> findApprovedForSemester(@Param("semesterId") Long semesterId);
+
+    @Query("""
+            select count(preference) > 0
+            from TeacherPreference preference
+            where preference.teacher.id = :teacherId
+              and preference.semester.id = :semesterId
+              and preference.preferenceType = :preferenceType
+              and preference.status in :statuses
+              and ((preference.dayOfWeek is null and :dayOfWeek is null) or preference.dayOfWeek = :dayOfWeek)
+              and ((preference.timeSlot is null and :timeSlotId is null) or preference.timeSlot.id = :timeSlotId)
+              and ((preference.preferenceDate is null and :preferenceDate is null) or preference.preferenceDate = :preferenceDate)
+            """)
+    boolean existsDuplicate(
+            @Param("teacherId") Long teacherId,
+            @Param("semesterId") Long semesterId,
+            @Param("preferenceType") String preferenceType,
+            @Param("dayOfWeek") Integer dayOfWeek,
+            @Param("timeSlotId") Long timeSlotId,
+            @Param("preferenceDate") LocalDate preferenceDate,
+            @Param("statuses") Collection<String> statuses
+    );
+}
--- a/backend/src/main/java/com/magistr/app/repository/TeacherSubjectRepository.java
+++ b/backend/src/main/java/com/magistr/app/repository/TeacherSubjectRepository.java
@@ -3,10 +3,38 @@ package com.magistr.app.repository;
 import com.magistr.app.model.TeacherSubject;
 import com.magistr.app.model.TeacherSubjectId;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;

 import java.util.List;

 public interface TeacherSubjectRepository extends JpaRepository<TeacherSubject, TeacherSubjectId> {
    List<TeacherSubject> findByUserId(Long userId);
    List<TeacherSubject> findBySubjectId(Long subjectId);
+
+    @Query(value = """
+            select subject_link.user_id
+            from teacher_subjects subject_link
+            where subject_link.subject_id = :subjectId
+              and (
+                    not exists (
+                        select 1
+                        from teacher_lesson_types configured_type
+                        where configured_type.user_id = subject_link.user_id
+                          and configured_type.subject_id = subject_link.subject_id
+                    )
+                    or exists (
+                        select 1
+                        from teacher_lesson_types supported_type
+                        where supported_type.user_id = subject_link.user_id
+                          and supported_type.subject_id = subject_link.subject_id
+                          and supported_type.lesson_type_id = :lessonTypeId
+                    )
+              )
+            order by subject_link.user_id
+            """, nativeQuery = true)
+    List<Long> findQualifiedTeacherIds(
+            @Param("subjectId") Long subjectId,
+            @Param("lessonTypeId") Long lessonTypeId
+    );
 }
--- a/backend/src/main/java/com/magistr/app/service/AcademicCalendarGridService.java
+++ b/backend/src/main/java/com/magistr/app/service/AcademicCalendarGridService.java
@@ -3,10 +3,10 @@ package com.magistr.app.service;
 import com.magistr.app.dto.AcademicCalendarGridDayDto;
 import com.magistr.app.model.AcademicCalendar;
 import com.magistr.app.model.AcademicCalendarActivityType;
-import com.magistr.app.model.AcademicCalendarDay;
+import com.magistr.app.model.AcademicCalendarPeriod;
 import com.magistr.app.model.AcademicYear;
 import com.magistr.app.repository.AcademicCalendarActivityTypeRepository;
-import com.magistr.app.repository.AcademicCalendarDayRepository;
+import com.magistr.app.repository.AcademicCalendarPeriodRepository;
 import com.magistr.app.repository.AcademicCalendarRepository;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -16,25 +16,27 @@ import org.springframework.transaction.support.TransactionSynchronizationManager
 import java.time.LocalDate;
 import java.time.temporal.ChronoUnit;
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.HashSet;
 import java.util.List;
 import java.util.NoSuchElementException;
+import java.util.Objects;
 import java.util.Set;

@Service
 public class AcademicCalendarGridService {

    private final AcademicCalendarRepository calendarRepository;
-    private final AcademicCalendarDayRepository calendarDayRepository;
+    private final AcademicCalendarPeriodRepository calendarPeriodRepository;
    private final AcademicCalendarActivityTypeRepository activityTypeRepository;
    private final ScheduleGeneratorService scheduleGeneratorService;

    public AcademicCalendarGridService(AcademicCalendarRepository calendarRepository,
-                                       AcademicCalendarDayRepository calendarDayRepository,
+                                       AcademicCalendarPeriodRepository calendarPeriodRepository,
                                       AcademicCalendarActivityTypeRepository activityTypeRepository,
                                       ScheduleGeneratorService scheduleGeneratorService) {
        this.calendarRepository = calendarRepository;
-        this.calendarDayRepository = calendarDayRepository;
+        this.calendarPeriodRepository = calendarPeriodRepository;
        this.activityTypeRepository = activityTypeRepository;
        this.scheduleGeneratorService = scheduleGeneratorService;
    }
@@ -47,18 +49,18 @@ public class AcademicCalendarGridService {
            throw new IllegalArgumentException("Передайте хотя бы одну ячейку графика");
        }

-        List<AcademicCalendarDay> replacement = buildReplacement(calendar, rows);
+        List<AcademicCalendarPeriod> replacement = buildReplacement(calendar, rows);

-        calendarDayRepository.deleteByCalendarId(id);
-        calendarDayRepository.flush();
-        calendarDayRepository.saveAll(replacement);
-        calendarDayRepository.flush();
+        calendarPeriodRepository.deleteByCalendarId(id);
+        calendarPeriodRepository.flush();
+        calendarPeriodRepository.saveAll(replacement);
+        calendarPeriodRepository.flush();
        clearScheduleCacheAfterCommit();
    }

-    private List<AcademicCalendarDay> buildReplacement(AcademicCalendar calendar,
+    private List<AcademicCalendarPeriod> buildReplacement(AcademicCalendar calendar,
                                                          List<AcademicCalendarGridDayDto> rows) {
-        List<AcademicCalendarDay> replacement = new ArrayList<>(rows.size());
+        List<ValidatedGridDay> validatedDays = new ArrayList<>(rows.size());
        Set<GridBusinessKey> uniqueRows = new HashSet<>();

        for (AcademicCalendarGridDayDto row : rows) {
@@ -75,19 +77,42 @@ public class AcademicCalendarGridService {
            if (!uniqueRows.add(businessKey)) {
                throw new IllegalArgumentException("Для курса и даты можно указать только одну активность");
            }
+            validatedDays.add(new ValidatedGridDay(
+                    row.courseNumber(),
+                    row.date(),
+                    resolveActivityType(row)
+            ));
+        }

-            AcademicCalendarDay day = new AcademicCalendarDay();
-            day.setAcademicCalendar(calendar);
-            day.setCourseNumber(row.courseNumber());
-            day.setDate(row.date());
-            day.setWeekNumber(row.weekNumber());
-            day.setDayOfWeek(row.dayOfWeek());
-            day.setActivityType(resolveActivityType(row));
-            replacement.add(day);
+        validatedDays.sort(Comparator
+                .comparing(ValidatedGridDay::courseNumber)
+                .thenComparing(ValidatedGridDay::date));
+
+        List<AcademicCalendarPeriod> replacement = new ArrayList<>();
+        AcademicCalendarPeriod currentPeriod = null;
+        for (ValidatedGridDay day : validatedDays) {
+            if (canExtend(currentPeriod, day)) {
+                currentPeriod.setEndDate(day.date());
+                continue;
+            }
+            currentPeriod = new AcademicCalendarPeriod();
+            currentPeriod.setAcademicCalendar(calendar);
+            currentPeriod.setCourseNumber(day.courseNumber());
+            currentPeriod.setStartDate(day.date());
+            currentPeriod.setEndDate(day.date());
+            currentPeriod.setActivityType(day.activityType());
+            replacement.add(currentPeriod);
        }
        return replacement;
    }

+    private boolean canExtend(AcademicCalendarPeriod period, ValidatedGridDay day) {
+        return period != null
+                && period.getCourseNumber().equals(day.courseNumber())
+                && period.getEndDate().plusDays(1).equals(day.date())
+                && Objects.equals(period.getActivityType().getId(), day.activityType().getId());
+    }
+
    private void validateRequiredFields(AcademicCalendarGridDayDto row) {
        if (row.courseNumber() == null
                || row.date() == null
@@ -155,4 +180,9 @@ public class AcademicCalendarGridService {

    private record GridBusinessKey(Integer courseNumber, LocalDate date) {
    }
+
+    private record ValidatedGridDay(Integer courseNumber,
+                                    LocalDate date,
+                                    AcademicCalendarActivityType activityType) {
+    }
 }
--- a/backend/src/main/java/com/magistr/app/service/AcademicDateService.java
+++ b/backend/src/main/java/com/magistr/app/service/AcademicDateService.java
@@ -1,7 +1,7 @@
 package com.magistr.app.service;

 import com.magistr.app.model.*;
-import com.magistr.app.repository.AcademicCalendarDayRepository;
+import com.magistr.app.repository.AcademicCalendarPeriodRepository;
 import com.magistr.app.repository.SemesterRepository;
 import com.magistr.app.repository.StudentGroupCalendarAssignmentRepository;
 import org.springframework.beans.factory.annotation.Value;
@@ -17,16 +17,16 @@ import java.util.stream.Collectors;
 public class AcademicDateService {

    private final SemesterRepository semesterRepository;
-    private final AcademicCalendarDayRepository calendarDayRepository;
+    private final AcademicCalendarPeriodRepository calendarPeriodRepository;
    private final StudentGroupCalendarAssignmentRepository assignmentRepository;
    private final boolean evenWeekIsUpper;

    public AcademicDateService(SemesterRepository semesterRepository,
-                               AcademicCalendarDayRepository calendarDayRepository,
+                               AcademicCalendarPeriodRepository calendarPeriodRepository,
                               StudentGroupCalendarAssignmentRepository assignmentRepository,
                               @Value("${app.schedule.even-week-is-upper:false}") boolean evenWeekIsUpper) {
        this.semesterRepository = semesterRepository;
-        this.calendarDayRepository = calendarDayRepository;
+        this.calendarPeriodRepository = calendarPeriodRepository;
        this.assignmentRepository = assignmentRepository;
        this.evenWeekIsUpper = evenWeekIsUpper;
    }
@@ -77,20 +77,54 @@ public class AcademicDateService {
        List<StudentGroupCalendarAssignment> assignments = groupIds.isEmpty() || academicYearIds.isEmpty()
                ? List.of()
                : assignmentRepository.findForScheduleBatch(groupIds, academicYearIds);
-        Set<Long> calendarIds = assignments.stream()
-                .map(StudentGroupCalendarAssignment::getAcademicCalendar)
-                .filter(Objects::nonNull)
-                .map(AcademicCalendar::getId)
-                .filter(Objects::nonNull)
-                .collect(Collectors.toCollection(LinkedHashSet::new));
-        List<AcademicCalendarDay> calendarDays = calendarIds.isEmpty()
-                || snapshotStart == null
-                || endDate == null
-                || endDate.isBefore(snapshotStart)
-                ? List.of()
-                : calendarDayRepository.findForScheduleBatch(calendarIds, snapshotStart, endDate);
+        List<AcademicCalendarPeriod> calendarPeriods = loadCalendarPeriods(
+                assignments,
+                snapshotStart,
+                endDate
+        );

-        return new ScheduleSnapshot(semesterSnapshot, assignments, calendarDays, snapshotStart, endDate);
+        return new ScheduleSnapshot(semesterSnapshot, assignments, calendarPeriods, snapshotStart, endDate);
+    }
+
+    private List<AcademicCalendarPeriod> loadCalendarPeriods(
+            Collection<StudentGroupCalendarAssignment> assignments,
+            LocalDate startDate,
+            LocalDate endDate) {
+        if (startDate == null || endDate == null || endDate.isBefore(startDate)) {
+            return List.of();
+        }
+
+        Map<Integer, Set<Long>> calendarIdsByCourse = new TreeMap<>();
+        for (StudentGroupCalendarAssignment assignment : assignments) {
+            if (assignment == null
+                    || assignment.getStudentGroup() == null
+                    || assignment.getAcademicYear() == null
+                    || assignment.getAcademicYear().getStartDate() == null
+                    || assignment.getAcademicCalendar() == null
+                    || assignment.getAcademicCalendar().getId() == null) {
+                continue;
+            }
+            int courseNumber = getCourseNumber(
+                    assignment.getStudentGroup(),
+                    assignment.getAcademicYear().getStartDate()
+            );
+            if (courseNumber < 1) {
+                continue;
+            }
+            calendarIdsByCourse.computeIfAbsent(courseNumber, ignored -> new LinkedHashSet<>())
+                    .add(assignment.getAcademicCalendar().getId());
+        }
+
+        List<AcademicCalendarPeriod> result = new ArrayList<>();
+        calendarIdsByCourse.forEach((courseNumber, calendarIds) ->
+                result.addAll(calendarPeriodRepository.findForScheduleBatch(
+                        calendarIds,
+                        courseNumber,
+                        startDate,
+                        endDate
+                ))
+        );
+        return result;
    }

    public int getWeekNumber(Semester semester, LocalDate date) {
@@ -126,12 +160,12 @@ public class AcademicDateService {
        }

        return assignmentRepository.findForSchedule(group.getId(), semester.getAcademicYear().getId())
-                .flatMap(assignment -> calendarDayRepository.findByCalendarIdAndCourseNumberAndDate(
+                .flatMap(assignment -> calendarPeriodRepository.findByCalendarIdAndCourseNumberAndDate(
                        assignment.getAcademicCalendar().getId(),
                        courseNumber,
                        date
                ))
-                .map(AcademicCalendarDay::getActivityType);
+                .map(AcademicCalendarPeriod::getActivityType);
    }

    public boolean isTheoryDay(StudentGroup group, Semester semester, LocalDate date) {
@@ -151,13 +185,13 @@ public class AcademicDateService {

        private final Map<LocalDate, Semester> semesterByDate;
        private final Map<GroupAcademicYearKey, StudentGroupCalendarAssignment> assignmentByGroupAndYear;
-        private final Map<CalendarDayKey, AcademicCalendarActivityType> activityByCalendarCourseAndDate;
+        private final Map<CalendarCourseKey, List<AcademicCalendarPeriod>> periodsByCalendarAndCourse;
        private final LocalDate startDate;
        private final LocalDate endDate;

        private ScheduleSnapshot(Collection<Semester> semesters,
                                 Collection<StudentGroupCalendarAssignment> assignments,
-                                 Collection<AcademicCalendarDay> calendarDays,
+                                 Collection<AcademicCalendarPeriod> calendarPeriods,
                                 LocalDate startDate,
                                 LocalDate endDate) {
            this.startDate = startDate;
@@ -171,14 +205,18 @@ public class AcademicDateService {
                            ),
                            Function.identity()
                    ));
-            this.activityByCalendarCourseAndDate = calendarDays.stream()
-                    .collect(Collectors.toUnmodifiableMap(
-                            day -> new CalendarDayKey(
-                                    day.getAcademicCalendar().getId(),
-                                    day.getCourseNumber(),
-                                    day.getDate()
+            this.periodsByCalendarAndCourse = calendarPeriods.stream()
+                    .collect(Collectors.groupingBy(
+                            period -> new CalendarCourseKey(
+                                    period.getAcademicCalendar().getId(),
+                                    period.getCourseNumber()
                            ),
-                            AcademicCalendarDay::getActivityType
+                            Collectors.collectingAndThen(
+                                    Collectors.toList(),
+                                    periods -> periods.stream()
+                                            .sorted(Comparator.comparing(AcademicCalendarPeriod::getStartDate))
+                                            .toList()
+                            )
                    ));
        }

@@ -200,9 +238,30 @@ public class AcademicDateService {
            return findAssignment(group, semester)
                    .map(StudentGroupCalendarAssignment::getAcademicCalendar)
                    .map(AcademicCalendar::getId)
-                    .map(calendarId -> activityByCalendarCourseAndDate.get(
-                            new CalendarDayKey(calendarId, courseNumber, date)
-                    ));
+                    .flatMap(calendarId -> findActivityType(calendarId, courseNumber, date));
+        }
+
+        private Optional<AcademicCalendarActivityType> findActivityType(Long calendarId,
+                                                                         int courseNumber,
+                                                                         LocalDate date) {
+            List<AcademicCalendarPeriod> periods = periodsByCalendarAndCourse.getOrDefault(
+                    new CalendarCourseKey(calendarId, courseNumber),
+                    List.of()
+            );
+            int left = 0;
+            int right = periods.size() - 1;
+            while (left <= right) {
+                int middle = (left + right) >>> 1;
+                AcademicCalendarPeriod period = periods.get(middle);
+                if (date.isBefore(period.getStartDate())) {
+                    right = middle - 1;
+                } else if (date.isAfter(period.getEndDate())) {
+                    left = middle + 1;
+                } else {
+                    return Optional.of(period.getActivityType());
+                }
+            }
+            return Optional.empty();
        }

        public boolean isTheoryDay(StudentGroup group, Semester semester, LocalDate date) {
@@ -268,6 +327,6 @@ public class AcademicDateService {
    private record GroupAcademicYearKey(Long groupId, Long academicYearId) {
    }

-    private record CalendarDayKey(Long calendarId, Integer courseNumber, LocalDate date) {
+    private record CalendarCourseKey(Long calendarId, Integer courseNumber) {
    }
 }
--- a/backend/src/main/java/com/magistr/app/service/AcademicPeriodService.java
+++ b/backend/src/main/java/com/magistr/app/service/AcademicPeriodService.java
@@ -3,8 +3,13 @@ package com.magistr.app.service;
 import com.magistr.app.dto.AcademicYearDto;
 import com.magistr.app.dto.SemesterDto;
 import com.magistr.app.model.AcademicYear;
+import com.magistr.app.model.ScheduleVersion;
+import com.magistr.app.model.ScheduleVersionHistory;
+import com.magistr.app.model.ScheduleVersionStatus;
 import com.magistr.app.model.Semester;
 import com.magistr.app.repository.AcademicYearRepository;
+import com.magistr.app.repository.ScheduleVersionHistoryRepository;
+import com.magistr.app.repository.ScheduleVersionRepository;
 import com.magistr.app.repository.SemesterRepository;
 import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.stereotype.Service;
@@ -12,6 +17,7 @@ import org.springframework.transaction.annotation.Transactional;
 import org.springframework.transaction.support.TransactionSynchronization;
 import org.springframework.transaction.support.TransactionSynchronizationManager;

+import java.time.Instant;
 import java.time.LocalDate;
 import java.util.NoSuchElementException;

@@ -26,13 +32,19 @@ public class AcademicPeriodService {
    private final AcademicYearRepository academicYearRepository;
    private final SemesterRepository semesterRepository;
    private final ScheduleGeneratorService scheduleGeneratorService;
+    private final ScheduleVersionRepository scheduleVersionRepository;
+    private final ScheduleVersionHistoryRepository scheduleVersionHistoryRepository;

    public AcademicPeriodService(AcademicYearRepository academicYearRepository,
                                 SemesterRepository semesterRepository,
-                                 ScheduleGeneratorService scheduleGeneratorService) {
+                                 ScheduleGeneratorService scheduleGeneratorService,
+                                 ScheduleVersionRepository scheduleVersionRepository,
+                                 ScheduleVersionHistoryRepository scheduleVersionHistoryRepository) {
        this.academicYearRepository = academicYearRepository;
        this.semesterRepository = semesterRepository;
        this.scheduleGeneratorService = scheduleGeneratorService;
+        this.scheduleVersionRepository = scheduleVersionRepository;
+        this.scheduleVersionHistoryRepository = scheduleVersionHistoryRepository;
    }

    @Transactional
@@ -102,6 +114,7 @@ public class AcademicPeriodService {
        semester.setAcademicYear(year);
        applySemester(semester, request);
        Semester saved = saveSemester(semester);
+        createInitialPublishedSchedule(saved);
        clearScheduleCacheAfterCommit();
        return saved;
    }
@@ -235,6 +248,28 @@ public class AcademicPeriodService {
        }
    }

+    private void createInitialPublishedSchedule(Semester semester) {
+        Instant now = Instant.now();
+        ScheduleVersion version = new ScheduleVersion();
+        version.setSemester(semester);
+        version.setVersionNumber(1);
+        version.setName("Основное расписание");
+        version.setStatus(ScheduleVersionStatus.PUBLISHED);
+        version.setPublishedAt(now);
+        ScheduleVersion saved = scheduleVersionRepository.saveAndFlush(version);
+
+        saveVersionHistory(saved, "CREATED", "Основное расписание создано вместе с семестром");
+        saveVersionHistory(saved, "PUBLISHED", "Начальная публикация расписания");
+    }
+
+    private void saveVersionHistory(ScheduleVersion version, String action, String reason) {
+        ScheduleVersionHistory history = new ScheduleVersionHistory();
+        history.setVersion(version);
+        history.setAction(action);
+        history.setReason(reason);
+        scheduleVersionHistoryRepository.save(history);
+    }
+
    private void clearScheduleCacheAfterCommit() {
        if (!TransactionSynchronizationManager.isSynchronizationActive()
                || !TransactionSynchronizationManager.isActualTransactionActive()) {
--- a/backend/src/main/java/com/magistr/app/service/AcademicStructureService.java
+++ b/backend/src/main/java/com/magistr/app/service/AcademicStructureService.java
@@ -4,13 +4,16 @@ import com.magistr.app.dto.AcademicCalendarDto;
 import com.magistr.app.dto.CreateGroupRequest;
 import com.magistr.app.dto.GroupCalendarAssignmentDto;
 import com.magistr.app.model.AcademicCalendar;
+import com.magistr.app.model.AcademicCalendarActivityType;
+import com.magistr.app.model.AcademicCalendarPeriod;
 import com.magistr.app.model.AcademicYear;
 import com.magistr.app.model.EducationForm;
 import com.magistr.app.model.Speciality;
 import com.magistr.app.model.SpecialtyProfile;
 import com.magistr.app.model.StudentGroup;
 import com.magistr.app.model.StudentGroupCalendarAssignment;
-import com.magistr.app.repository.AcademicCalendarDayRepository;
+import com.magistr.app.repository.AcademicCalendarActivityTypeRepository;
+import com.magistr.app.repository.AcademicCalendarPeriodRepository;
 import com.magistr.app.repository.AcademicCalendarRepository;
 import com.magistr.app.repository.AcademicCalendarSubjectRepository;
 import com.magistr.app.repository.AcademicYearRepository;
@@ -28,14 +31,18 @@ import org.springframework.transaction.annotation.Transactional;
 import org.springframework.transaction.support.TransactionSynchronization;
 import org.springframework.transaction.support.TransactionSynchronizationManager;

+import java.util.ArrayList;
 import java.util.List;
 import java.util.NoSuchElementException;

@Service
 public class AcademicStructureService {

+    private static final String THEORY_ACTIVITY_CODE = "Т";
+
    private final AcademicCalendarRepository calendarRepository;
-    private final AcademicCalendarDayRepository calendarDayRepository;
+    private final AcademicCalendarPeriodRepository calendarPeriodRepository;
+    private final AcademicCalendarActivityTypeRepository activityTypeRepository;
    private final AcademicCalendarSubjectRepository calendarSubjectRepository;
    private final AcademicYearRepository academicYearRepository;
    private final SpecialtiesRepository specialtiesRepository;
@@ -47,7 +54,8 @@ public class AcademicStructureService {
    private final ScheduleGeneratorService scheduleGeneratorService;

    public AcademicStructureService(AcademicCalendarRepository calendarRepository,
-                                    AcademicCalendarDayRepository calendarDayRepository,
+                                    AcademicCalendarPeriodRepository calendarPeriodRepository,
+                                    AcademicCalendarActivityTypeRepository activityTypeRepository,
                                    AcademicCalendarSubjectRepository calendarSubjectRepository,
                                    AcademicYearRepository academicYearRepository,
                                    SpecialtiesRepository specialtiesRepository,
@@ -58,7 +66,8 @@ public class AcademicStructureService {
                                    SubgroupRepository subgroupRepository,
                                    ScheduleGeneratorService scheduleGeneratorService) {
        this.calendarRepository = calendarRepository;
-        this.calendarDayRepository = calendarDayRepository;
+        this.calendarPeriodRepository = calendarPeriodRepository;
+        this.activityTypeRepository = activityTypeRepository;
        this.calendarSubjectRepository = calendarSubjectRepository;
        this.academicYearRepository = academicYearRepository;
        this.specialtiesRepository = specialtiesRepository;
@@ -82,6 +91,41 @@ public class AcademicStructureService {
        return saved;
    }

+    @Transactional
+    public AcademicCalendar createCalendar(AcademicCalendarDto request) {
+        validateCalendarRequest(request);
+        CalendarDimensions dimensions = resolveCalendarDimensions(request);
+        AcademicCalendarActivityType theoryActivity = activityTypeRepository.findByCode(THEORY_ACTIVITY_CODE)
+                .filter(activity -> Boolean.TRUE.equals(activity.getAllowSchedule()))
+                .orElseThrow(() -> new IllegalArgumentException(
+                        "Код активности «Т», разрешающий обычные занятия, не найден"
+                ));
+
+        AcademicCalendar calendar = new AcademicCalendar();
+        calendar.setTitle(AcademicCalendarTitleBuilder.build(
+                dimensions.academicYear(),
+                dimensions.speciality(),
+                dimensions.profile(),
+                dimensions.studyForm()
+        ));
+        applyCalendarDimensions(calendar, dimensions, request.courseCount());
+        AcademicCalendar saved = saveCalendar(calendar);
+
+        List<AcademicCalendarPeriod> defaultPeriods = new ArrayList<>(request.courseCount());
+        for (int courseNumber = 1; courseNumber <= request.courseCount(); courseNumber++) {
+            AcademicCalendarPeriod period = new AcademicCalendarPeriod();
+            period.setAcademicCalendar(saved);
+            period.setCourseNumber(courseNumber);
+            period.setStartDate(dimensions.academicYear().getStartDate());
+            period.setEndDate(dimensions.academicYear().getEndDate());
+            period.setActivityType(theoryActivity);
+            defaultPeriods.add(period);
+        }
+        calendarPeriodRepository.saveAll(defaultPeriods);
+        clearScheduleCacheAfterCommit();
+        return saved;
+    }
+
    @Transactional
    public AcademicCalendar updateCalendar(Long id, AcademicCalendarDto request) {
        validateCalendarRequest(request);
@@ -106,7 +150,7 @@ public class AcademicStructureService {
                    "Нельзя изменить график: сохранённые назначения групп станут несовместимыми"
            );
        }
-        if (calendarDayRepository.existsByAcademicCalendarIdAndCourseNumberGreaterThan(
+        if (calendarPeriodRepository.existsByAcademicCalendarIdAndCourseNumberGreaterThan(
                id, request.courseCount())) {
            throw new ScheduleConflictException(
                    "Нельзя уменьшить количество курсов: в сетке есть данные старших курсов"
@@ -118,7 +162,7 @@ public class AcademicStructureService {
                    "Нельзя уменьшить количество курсов: есть дисциплины старших семестров"
            );
        }
-        if (calendarDayRepository.existsOutsideDateRange(
+        if (calendarPeriodRepository.existsOutsideDateRange(
                id,
                candidate.academicYear().getStartDate(),
                candidate.academicYear().getEndDate())) {
--- a/backend/src/main/java/com/magistr/app/service/ScheduleGeneratorService.java
+++ b/backend/src/main/java/com/magistr/app/service/ScheduleGeneratorService.java
@@ -95,6 +95,30 @@ public class ScheduleGeneratorService {
        return buildScheduleForGroupsInternal(groupSnapshot, startDate, endDate);
    }

+    public List<RenderedLessonDto> buildScheduleForVersion(Long versionId,
+                                                           LocalDate startDate,
+                                                           LocalDate endDate) {
+        validateRange(startDate, endDate);
+        if (versionId == null) {
+            throw new IllegalArgumentException("Версия расписания обязательна");
+        }
+        List<ScheduleRule> rules = scheduleRuleRepository.findActiveByVersionIdWithDetails(versionId, null);
+        List<StudentGroup> groups = rules.stream()
+                .flatMap(rule -> rule.getGroups().stream())
+                .filter(group -> group.getId() != null)
+                .collect(Collectors.toMap(
+                        StudentGroup::getId,
+                        group -> group,
+                        (first, ignored) -> first,
+                        LinkedHashMap::new
+                ))
+                .values()
+                .stream()
+                .toList();
+        List<Semester> semesters = academicDateService.findSemesters(startDate, endDate);
+        return buildScheduleForGroupsInternal(groups, startDate, endDate, rules, semesters);
+    }
+
    private List<RenderedLessonDto> buildScheduleForGroupsInternal(List<StudentGroup> groups,
                                                                   LocalDate startDate,
                                                                   LocalDate endDate) {
@@ -113,6 +137,24 @@ public class ScheduleGeneratorService {
                .map(StudentGroup::getId)
                .collect(Collectors.toCollection(LinkedHashSet::new));
        List<ScheduleRule> rules = scheduleRuleRepository.findByGroupIdsAndSemesterIds(groupIds, semesterIds);
+        return buildScheduleForGroupsInternal(groups, startDate, endDate, rules, semesters);
+    }
+
+    private List<RenderedLessonDto> buildScheduleForGroupsInternal(List<StudentGroup> groups,
+                                                                   LocalDate startDate,
+                                                                   LocalDate endDate,
+                                                                   List<ScheduleRule> rules,
+                                                                   List<Semester> semesters) {
+        if (groups.isEmpty()) {
+            return List.of();
+        }
+
+        if (semesters.isEmpty()) {
+            return List.of();
+        }
+        Set<Long> groupIds = groups.stream()
+                .map(StudentGroup::getId)
+                .collect(Collectors.toCollection(LinkedHashSet::new));
        AcademicDateService.ScheduleSnapshot dateSnapshot = academicDateService
                .createScheduleSnapshot(groups, semesters, endDate);
        TimeSlotSnapshot timeSlotSnapshot = loadTimeSlotSnapshot(startDate, endDate, rules);
--- a/backend/src/main/java/com/magistr/app/service/ScheduleOverrideService.java
+++ b/backend/src/main/java/com/magistr/app/service/ScheduleOverrideService.java
@@ -56,6 +56,7 @@ public class ScheduleOverrideService {
    private final PostgreSqlAdvisoryLock advisoryLock;
    private final AcademicDateService academicDateService;
    private final EffectiveTimeSlotService effectiveTimeSlotService;
+    private TeacherAvailabilityPolicyService teacherAvailabilityPolicyService;

    @Autowired
    public ScheduleOverrideService(ScheduleOverrideRepository scheduleOverrideRepository,
@@ -106,6 +107,11 @@ public class ScheduleOverrideService {
        );
    }

+    @Autowired(required = false)
+    void setTeacherAvailabilityPolicyService(TeacherAvailabilityPolicyService teacherAvailabilityPolicyService) {
+        this.teacherAvailabilityPolicyService = teacherAvailabilityPolicyService;
+    }
+
    @Transactional(readOnly = true)
    public List<ScheduleOverrideDto> getAll(LocalDate startDate, LocalDate endDate) {
        if ((startDate == null) != (endDate == null)) {
@@ -184,6 +190,43 @@ public class ScheduleOverrideService {
        return validateAndPersist(null, command);
    }

+    /**
+     * Проверяет кандидат мастера замены тем же механизмом, что и обычное точечное изменение,
+     * но не блокирует строки и не сохраняет результат.
+     */
+    @Transactional(readOnly = true)
+    public void validateCandidate(ScheduleOverrideDto request) {
+        OverrideCommand command = validateAndNormalize(request);
+        if (scheduleOverrideRepository
+                .findByBaseRuleSlotIdAndLessonDate(command.baseRuleSlotId(), command.lessonDate())
+                .isPresent()) {
+            throw new ScheduleConflictException(
+                    "Для выбранной базовой пары и даты уже существует точечное изменение"
+            );
+        }
+        List<RenderedLessonDto> baseDay = scheduleQueryService.buildBaseDayForAllGroups(command.lessonDate());
+        List<RenderedLessonDto> sourceOccurrences = baseDay.stream()
+                .filter(lesson -> Objects.equals(lesson.scheduleRuleSlotId(), command.baseRuleSlotId()))
+                .filter(lesson -> Objects.equals(lesson.date(), command.lessonDate()))
+                .toList();
+        if (sourceOccurrences.isEmpty()) {
+            throw new IllegalArgumentException(
+                    "На выбранную дату базовая пара не формируется по правилам расписания"
+            );
+        }
+        ResolvedReferences references = resolveReferences(command, sourceOccurrences);
+        validateTargetDate(command, references.baseRuleSlot(), sourceOccurrences);
+        if (!"CANCEL".equals(command.action())) {
+            validateEffectiveResult(
+                    null,
+                    command,
+                    buildCandidate(command, references),
+                    baseDay,
+                    sourceOccurrences
+            );
+        }
+    }
+
    @Transactional
    public ScheduleOverrideDto update(Long id, ScheduleOverrideDto request) {
        OverrideCommand command = validateAndNormalize(request);
@@ -294,6 +337,7 @@ public class ScheduleOverrideService {
                .map(EffectiveSourceTuple::from)
                .collect(Collectors.toSet());
        validateActionSpecificChange(command.action(), sourceOccurrences, candidateOccurrences);
+        validateTeacherAvailability(candidate, candidateOccurrences);
        if (sourceTuples.equals(candidateTuples)) {
            throw new IllegalArgumentException(
                    "Точечное изменение должно фактически менять время, преподавателя, аудиторию или формат пары"
@@ -308,6 +352,27 @@ public class ScheduleOverrideService {
        validateResourceConflicts(candidateOccurrences, otherOccurrences, subgroupToGroup);
    }

+    private void validateTeacherAvailability(
+            ScheduleOverride candidate,
+            List<RenderedLessonDto> candidateOccurrences
+    ) {
+        if (teacherAvailabilityPolicyService == null
+                || candidate.getBaseRuleSlot() == null
+                || candidate.getBaseRuleSlot().getScheduleRule() == null
+                || candidate.getBaseRuleSlot().getScheduleRule().getSemester() == null) {
+            return;
+        }
+        Long semesterId = candidate.getBaseRuleSlot().getScheduleRule().getSemester().getId();
+        for (RenderedLessonDto occurrence : candidateOccurrences) {
+            teacherAvailabilityPolicyService.assertLessonAvailable(
+                    occurrence.teacherId(),
+                    semesterId,
+                    occurrence.date(),
+                    occurrence.timeSlotId()
+            );
+        }
+    }
+
    private boolean isCandidateOccurrence(RenderedLessonDto lesson, OverrideCommand command) {
        return Objects.equals(lesson.scheduleRuleSlotId(), command.baseRuleSlotId())
                && (Objects.equals(lesson.originalLessonDate(), command.lessonDate())
--- a/backend/src/main/java/com/magistr/app/service/ScheduleQualityService.java
+++ b/backend/src/main/java/com/magistr/app/service/ScheduleQualityService.java
--- a/backend/src/main/java/com/magistr/app/service/ScheduleQueryService.java
+++ b/backend/src/main/java/com/magistr/app/service/ScheduleQueryService.java
@@ -3,6 +3,7 @@ package com.magistr.app.service;
 import com.magistr.app.dto.RenderedLessonDto;
 import com.magistr.app.model.ScheduleOverride;
 import com.magistr.app.model.StudentGroup;
+import com.magistr.app.model.TeacherDepartmentAssignment;
 import com.magistr.app.repository.GroupRepository;
 import com.magistr.app.repository.ScheduleOverrideRepository;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -24,25 +25,38 @@ public class ScheduleQueryService {
    private final ScheduleOverrideRepository scheduleOverrideRepository;
    private final StudentGroupLifecycleService groupLifecycleService;
    private final AcademicDateService academicDateService;
+    private final TeacherDepartmentService teacherDepartmentService;

    @Autowired
    public ScheduleQueryService(ScheduleGeneratorService scheduleGeneratorService,
                                GroupRepository groupRepository,
                                ScheduleOverrideRepository scheduleOverrideRepository,
                                StudentGroupLifecycleService groupLifecycleService,
-                                AcademicDateService academicDateService) {
+                                AcademicDateService academicDateService,
+                                TeacherDepartmentService teacherDepartmentService) {
        this.scheduleGeneratorService = scheduleGeneratorService;
        this.groupRepository = groupRepository;
        this.scheduleOverrideRepository = scheduleOverrideRepository;
        this.groupLifecycleService = groupLifecycleService;
        this.academicDateService = academicDateService;
+        this.teacherDepartmentService = teacherDepartmentService;
+    }
+
+    ScheduleQueryService(ScheduleGeneratorService scheduleGeneratorService,
+                         GroupRepository groupRepository,
+                         ScheduleOverrideRepository scheduleOverrideRepository,
+                         StudentGroupLifecycleService groupLifecycleService,
+                         AcademicDateService academicDateService) {
+        this(scheduleGeneratorService, groupRepository, scheduleOverrideRepository,
+                groupLifecycleService, academicDateService, null);
    }

    ScheduleQueryService(ScheduleGeneratorService scheduleGeneratorService,
                         GroupRepository groupRepository,
                         ScheduleOverrideRepository scheduleOverrideRepository,
                         StudentGroupLifecycleService groupLifecycleService) {
-        this(scheduleGeneratorService, groupRepository, scheduleOverrideRepository, groupLifecycleService, null);
+        this(scheduleGeneratorService, groupRepository, scheduleOverrideRepository,
+                groupLifecycleService, null, null);
    }

    /**
@@ -192,10 +206,19 @@ public class ScheduleQueryService {
                .findByLessonDateBetweenWithDetails(startDate, endDate);
        generatedLessons = new ArrayList<>(generatedLessons);
        addOverrideSourceOccurrences(generatedLessons, overrideSnapshot, scopedGroups);
-        List<RenderedLessonDto> lessons = applyOverrides(generatedLessons, null, overrideSnapshot).stream()
+        List<RenderedLessonDto> effectiveLessons = applyOverrides(generatedLessons, null, overrideSnapshot);
+        Map<Long, List<TeacherDepartmentAssignment>> assignmentsByTeacher =
+                assignmentsByTeacher(effectiveLessons, departmentId, startDate, endDate);
+        List<RenderedLessonDto> lessons = effectiveLessons.stream()
                .filter(lesson -> !lesson.date().isBefore(startDate) && !lesson.date().isAfter(endDate))
                .filter(lesson -> teacherId == null || Objects.equals(lesson.teacherId(), teacherId))
                .filter(lesson -> classroomId == null || Objects.equals(lesson.classroomId(), classroomId))
+                .filter(lesson -> departmentId == null || teacherDepartmentService
+                        .hasDepartmentAssignmentAtDate(
+                                assignmentsByTeacher.getOrDefault(lesson.teacherId(), List.of()),
+                                departmentId,
+                                lesson.date()
+                        ))
                .filter(lesson -> subjectId == null || Objects.equals(lesson.subjectId(), subjectId))
                .filter(lesson -> lessonTypeId == null || Objects.equals(lesson.lessonTypeId(), lessonTypeId))
                .filter(lesson -> timeSlotId == null || Objects.equals(lesson.timeSlotId(), timeSlotId))
@@ -204,6 +227,29 @@ public class ScheduleQueryService {
        return deduplicate(lessons);
    }

+    private Map<Long, List<TeacherDepartmentAssignment>> assignmentsByTeacher(
+            List<RenderedLessonDto> lessons,
+            Long departmentId,
+            LocalDate startDate,
+            LocalDate endDate
+    ) {
+        if (departmentId == null) {
+            return Map.of();
+        }
+        if (teacherDepartmentService == null) {
+            throw new IllegalStateException("Сервис кафедральных связей преподавателей недоступен");
+        }
+        Set<Long> teacherIds = lessons.stream()
+                .map(RenderedLessonDto::teacherId)
+                .filter(Objects::nonNull)
+                .collect(Collectors.toCollection(LinkedHashSet::new));
+        return teacherDepartmentService.findAssignmentsForTeachersBetween(
+                teacherIds,
+                startDate,
+                endDate
+        );
+    }
+
    private void addOverrideSourceOccurrences(
            List<RenderedLessonDto> generatedLessons,
            Collection<ScheduleOverride> overrideSnapshot,
@@ -395,12 +441,10 @@ public class ScheduleQueryService {
                    .map(List::of)
                    .orElse(List.of());
        }
-        List<StudentGroup> groups;
-        if (departmentId != null) {
-            groups = groupRepository.findByDepartmentId(departmentId);
-        } else {
-            groups = groupRepository.findAll();
-        }
+        // Кафедральный scope определяется по преподавателю на дату занятия,
+        // а не по выпускающей кафедре учебной группы. Фильтрация выполняется
+        // после генерации и применения точечных изменений.
+        List<StudentGroup> groups = groupRepository.findAll();
        groups = groups.stream()
                .filter(group -> groupLifecycleService.mayHaveScheduleInRange(group, startDate, endDate))
                .toList();
--- a/backend/src/main/java/com/magistr/app/service/ScheduleRuleService.java
+++ b/backend/src/main/java/com/magistr/app/service/ScheduleRuleService.java
@@ -2,6 +2,7 @@ package com.magistr.app.service;

 import com.magistr.app.dto.ScheduleRuleDto;
 import com.magistr.app.dto.ScheduleRuleSlotDto;
+import com.magistr.app.config.auth.AuthContext;
 import com.magistr.app.model.Classroom;
 import com.magistr.app.model.LessonType;
 import com.magistr.app.model.LifecycleEntity;
@@ -10,6 +11,8 @@ import com.magistr.app.model.ScheduleLessonCategory;
 import com.magistr.app.model.ScheduleParity;
 import com.magistr.app.model.ScheduleRule;
 import com.magistr.app.model.ScheduleRuleSlot;
+import com.magistr.app.model.ScheduleVersion;
+import com.magistr.app.model.ScheduleVersionStatus;
 import com.magistr.app.model.Semester;
 import com.magistr.app.model.StudentGroup;
 import com.magistr.app.model.Subgroup;
@@ -20,11 +23,14 @@ import com.magistr.app.repository.ClassroomRepository;
 import com.magistr.app.repository.GroupRepository;
 import com.magistr.app.repository.LessonTypesRepository;
 import com.magistr.app.repository.ScheduleRuleRepository;
+import com.magistr.app.repository.ScheduleRuleSlotRepository;
+import com.magistr.app.repository.ScheduleVersionRepository;
 import com.magistr.app.repository.SemesterRepository;
 import com.magistr.app.repository.SubjectRepository;
 import com.magistr.app.repository.SubgroupRepository;
 import com.magistr.app.repository.TimeSlotRepository;
 import com.magistr.app.repository.UserRepository;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;

@@ -70,6 +76,9 @@ public class ScheduleRuleService {
    private final LessonTypesRepository lessonTypesRepository;
    private final SubgroupRepository subgroupRepository;
    private final ScheduleGeneratorService scheduleGeneratorService;
+    private TeacherAvailabilityPolicyService teacherAvailabilityPolicyService;
+    private ScheduleVersionRepository scheduleVersionRepository;
+    private ScheduleRuleSlotRepository scheduleRuleSlotRepository;

    public ScheduleRuleService(ScheduleRuleRepository scheduleRuleRepository,
                               SubjectRepository subjectRepository,
@@ -93,9 +102,32 @@ public class ScheduleRuleService {
        this.scheduleGeneratorService = scheduleGeneratorService;
    }

+    @Autowired(required = false)
+    void setTeacherAvailabilityPolicyService(TeacherAvailabilityPolicyService teacherAvailabilityPolicyService) {
+        this.teacherAvailabilityPolicyService = teacherAvailabilityPolicyService;
+    }
+
+    @Autowired(required = false)
+    void setScheduleVersionRepository(ScheduleVersionRepository scheduleVersionRepository) {
+        this.scheduleVersionRepository = scheduleVersionRepository;
+    }
+
+    @Autowired(required = false)
+    void setScheduleRuleSlotRepository(ScheduleRuleSlotRepository scheduleRuleSlotRepository) {
+        this.scheduleRuleSlotRepository = scheduleRuleSlotRepository;
+    }
+
    @Transactional(readOnly = true)
    public List<ScheduleRuleDto> getAll(Long semesterId, Long groupId) {
-        return scheduleRuleRepository.findAllWithDetails().stream()
+        return getAll(semesterId, groupId, null);
+    }
+
+    @Transactional(readOnly = true)
+    public List<ScheduleRuleDto> getAll(Long semesterId, Long groupId, Long scheduleVersionId) {
+        List<ScheduleRule> source = scheduleVersionId == null
+                ? scheduleRuleRepository.findAllWithDetails()
+                : scheduleRuleRepository.findActiveByVersionIdWithDetails(scheduleVersionId, null);
+        return source.stream()
                .filter(ScheduleRule::isActiveRecord)
                .filter(rule -> semesterId == null || Objects.equals(rule.getSemester().getId(), semesterId))
                .filter(rule -> groupId == null || rule.getGroups().stream()
@@ -120,11 +152,17 @@ public class ScheduleRuleService {
        Semester semester = semesterRepository.findByIdForUpdate(request.semesterId())
                .orElseThrow(() -> new IllegalArgumentException("Семестр не найден"));

-        ScheduleRule candidate = buildCandidate(request, semester);
+        ScheduleVersion version = resolveEditableVersion(request.scheduleVersionId(), semester.getId());
+
+        ScheduleRule candidate = buildCandidate(request, semester, version);
        validateCandidate(candidate);
        validateAgainstSavedRules(candidate, null);

        ScheduleRule saved = scheduleRuleRepository.saveAndFlush(candidate);
+        if (saved.getVersionGroupId() == null && saved.getId() != null) {
+            saved.setVersionGroupId(saved.getId());
+            saved = scheduleRuleRepository.saveAndFlush(saved);
+        }
        scheduleGeneratorService.clearCache();
        return toDto(saved);
    }
@@ -137,6 +175,7 @@ public class ScheduleRuleService {
        // определён по актуальному состоянию и два update одного правила не расходятся.
        ScheduleRule managedRule = scheduleRuleRepository.findByIdForUpdate(id)
                .orElseThrow(() -> new NoSuchElementException("Правило расписания не найдено"));
+        lockAndEnsureEditableRule(managedRule);
        Long oldSemesterId = managedRule.getSemester().getId();

        Map<Long, Semester> lockedSemesters = lockSemestersInStableOrder(
@@ -147,11 +186,22 @@ public class ScheduleRuleService {
            throw new IllegalArgumentException("Семестр не найден");
        }

-        ScheduleRule candidate = buildCandidate(request, targetSemester);
+        if (managedRule.getScheduleVersion() != null
+                && request.scheduleVersionId() != null
+                && !Objects.equals(managedRule.getScheduleVersion().getId(), request.scheduleVersionId())) {
+            throw new IllegalArgumentException("Нельзя переносить правило между версиями расписания");
+        }
+        if (managedRule.getScheduleVersion() != null
+                && !Objects.equals(managedRule.getScheduleVersion().getSemester().getId(), targetSemester.getId())) {
+            throw new IllegalArgumentException("Нельзя переносить правило в другой семестр внутри версии");
+        }
+
+        ScheduleRule candidate = buildCandidate(request, targetSemester, managedRule.getScheduleVersion());
+        candidate.setVersionGroupId(managedRule.getVersionGroupId());
        validateCandidate(candidate);
        validateAgainstSavedRules(candidate, managedRule.getId());

-        applyCandidate(managedRule, candidate);
+        applyCandidate(managedRule, candidate, request.slots());
        ScheduleRule saved = scheduleRuleRepository.saveAndFlush(managedRule);
        scheduleGeneratorService.clearCache();
        return toDto(saved);
@@ -161,6 +211,7 @@ public class ScheduleRuleService {
    public void archive(Long id) {
        ScheduleRule rule = scheduleRuleRepository.findByIdForUpdate(id)
                .orElseThrow(() -> new NoSuchElementException("Правило расписания не найдено"));
+        lockAndEnsureEditableRule(rule);
        Long semesterId = rule.getSemester().getId();
        semesterRepository.findByIdForUpdate(semesterId)
                .orElseThrow(() -> new NoSuchElementException("Семестр правила не найден"));
@@ -267,7 +318,7 @@ public class ScheduleRuleService {
        normalizeLessonFormat(slot.lessonFormat());
    }

-    private ScheduleRule buildCandidate(ScheduleRuleDto request, Semester semester) {
+    private ScheduleRule buildCandidate(ScheduleRuleDto request, Semester semester, ScheduleVersion version) {
        Subject subject = subjectRepository.findById(request.subjectId())
                .orElseThrow(() -> new IllegalArgumentException("Дисциплина не найдена"));
        if (subject.isArchivedRecord()) {
@@ -286,6 +337,11 @@ public class ScheduleRuleService {
        ScheduleRule candidate = new ScheduleRule();
        candidate.setSubject(subject);
        candidate.setSemester(semester);
+        candidate.setScheduleVersion(version);
+        Long currentUserId = AuthContext.currentUserId();
+        if (currentUserId != null) {
+            userRepository.findById(currentUserId).ifPresent(candidate::setCreatedBy);
+        }
        candidate.setLectureAcademicHours(request.lectureAcademicHours());
        candidate.setLaboratoryAcademicHours(request.laboratoryAcademicHours());
        candidate.setPracticeAcademicHours(request.practiceAcademicHours());
@@ -424,6 +480,21 @@ public class ScheduleRuleService {
        List<ScheduleRuleSlot> slots = new ArrayList<>(candidate.getSlots());
        validateExactDuplicates(slots);
        validateInternalConflicts(slots);
+        validateTeacherAvailability(candidate, slots);
+    }
+
+    private void validateTeacherAvailability(ScheduleRule candidate, List<ScheduleRuleSlot> slots) {
+        if (teacherAvailabilityPolicyService == null) return;
+        Map<ScheduleRuleSlot, Set<Integer>> activeWeeks = activeWeeksBySlot(slots);
+        for (ScheduleRuleSlot slot : slots) {
+            teacherAvailabilityPolicyService.assertRuleSlotAvailable(
+                    teacherId(slot),
+                    candidate.getSemester(),
+                    slot.getDayOfWeek(),
+                    timeSlotId(slot),
+                    activeWeeks.get(slot)
+            );
+        }
    }

    private void validateExactDuplicates(List<ScheduleRuleSlot> slots) {
@@ -483,8 +554,12 @@ public class ScheduleRuleService {

    private void validateAgainstSavedRules(ScheduleRule candidate, Long excludeRuleId) {
        Map<ScheduleRuleSlot, Set<Integer>> candidateActiveWeeks = activeWeeksBySlot(candidate.getSlots());
-        ScheduleRuleConflict conflict = scheduleRuleRepository
-                .findActiveBySemesterIdWithDetails(candidate.getSemester().getId(), excludeRuleId)
+        List<ScheduleRule> savedRules = candidate.getScheduleVersion() == null
+                ? scheduleRuleRepository.findActiveBySemesterIdWithDetails(
+                        candidate.getSemester().getId(), excludeRuleId)
+                : scheduleRuleRepository.findActiveByVersionIdWithDetails(
+                        candidate.getScheduleVersion().getId(), excludeRuleId);
+        ScheduleRuleConflict conflict = savedRules
                .stream()
                .filter(ScheduleRule::isActiveRecord)
                .filter(rule -> !Objects.equals(rule.getId(), excludeRuleId))
@@ -737,7 +812,9 @@ public class ScheduleRuleService {
                .toList();
    }

-    private void applyCandidate(ScheduleRule managedRule, ScheduleRule candidate) {
+    private void applyCandidate(ScheduleRule managedRule,
+                                ScheduleRule candidate,
+                                List<ScheduleRuleSlotDto> requestedSlots) {
        managedRule.setSubject(candidate.getSubject());
        managedRule.setSemester(candidate.getSemester());
        managedRule.setLectureAcademicHours(candidate.getLectureAcademicHours());
@@ -749,11 +826,54 @@ public class ScheduleRuleService {

        managedRule.getGroups().clear();
        managedRule.getGroups().addAll(candidate.getGroups());
-        managedRule.getSlots().clear();
-        for (ScheduleRuleSlot slot : candidate.getSlots()) {
-            slot.setScheduleRule(managedRule);
-            managedRule.getSlots().add(slot);
+        List<ScheduleRuleSlot> candidateSlots = new ArrayList<>(candidate.getSlots());
+        Map<Long, ScheduleRuleSlot> currentSlotsById = managedRule.getSlots().stream()
+                .filter(slot -> slot.getId() != null)
+                .collect(Collectors.toMap(ScheduleRuleSlot::getId, Function.identity()));
+        Set<Long> retainedSlotIds = new HashSet<>();
+        Set<ScheduleRuleSlot> updatedSlots = new LinkedHashSet<>();
+
+        for (int index = 0; index < candidateSlots.size(); index++) {
+            ScheduleRuleSlot candidateSlot = candidateSlots.get(index);
+            Long requestedSlotId = requestedSlots.get(index).id();
+            if (requestedSlotId == null) {
+                candidateSlot.setScheduleRule(managedRule);
+                updatedSlots.add(candidateSlot);
+                continue;
            }
+
+            ScheduleRuleSlot existingSlot = currentSlotsById.get(requestedSlotId);
+            if (existingSlot == null) {
+                throw new IllegalArgumentException("Слот не принадлежит редактируемому правилу");
+            }
+            retainedSlotIds.add(requestedSlotId);
+            copySlot(existingSlot, candidateSlot);
+            updatedSlots.add(existingSlot);
+        }
+
+        List<Long> removedSlotIds = currentSlotsById.keySet().stream()
+                .filter(id -> !retainedSlotIds.contains(id))
+                .toList();
+        if (!removedSlotIds.isEmpty()
+                && scheduleRuleSlotRepository != null
+                && scheduleRuleSlotRepository.hasProtectedReferences(removedSlotIds)) {
+            throw new IllegalArgumentException(
+                    "Нельзя удалить слот: на него ссылаются точечные изменения, заявки преподавателей или решения по отсутствиям"
+            );
+        }
+        managedRule.getSlots().clear();
+        managedRule.getSlots().addAll(updatedSlots);
+    }
+
+    private void copySlot(ScheduleRuleSlot target, ScheduleRuleSlot source) {
+        target.setDayOfWeek(source.getDayOfWeek());
+        target.setParity(source.getParity());
+        target.setTimeSlot(source.getTimeSlot());
+        target.setSubgroups(source.getSubgroups());
+        target.setTeacher(source.getTeacher());
+        target.setClassroom(source.getClassroom());
+        target.setLessonType(source.getLessonType());
+        target.setLessonFormat(source.getLessonFormat());
    }

    private ScheduleRuleDto toDto(ScheduleRule rule) {
@@ -783,10 +903,77 @@ public class ScheduleRuleService {
                rule.getPracticeStartWeek(),
                groups.stream().map(StudentGroup::getId).toList(),
                groups.stream().map(StudentGroup::getName).toList(),
-                slots
+                slots,
+                rule.getScheduleVersion() == null ? null : rule.getScheduleVersion().getId()
        );
    }

+    @Transactional(readOnly = true)
+    public List<String> validateVersion(Long scheduleVersionId) {
+        if (scheduleVersionId == null) {
+            return List.of("Версия расписания не выбрана");
+        }
+        List<ScheduleRule> rules = scheduleRuleRepository
+                .findActiveByVersionIdWithDetails(scheduleVersionId, null);
+        if (rules.isEmpty()) {
+            return List.of("В черновике нет ни одного правила расписания");
+        }
+        LinkedHashSet<String> issues = new LinkedHashSet<>();
+        for (ScheduleRule rule : rules) {
+            if (rule.getSlots().isEmpty()) {
+                issues.add("Правило «" + rule.getSubject().getName() + "» не содержит слотов");
+                continue;
+            }
+            try {
+                validateCandidate(rule);
+                validateAgainstSavedRules(rule, rule.getId());
+            } catch (IllegalArgumentException | ScheduleRuleConflictException exception) {
+                issues.add("Правило «" + rule.getSubject().getName() + "»: " + exception.getMessage());
+            }
+        }
+        return List.copyOf(issues);
+    }
+
+    private ScheduleVersion resolveEditableVersion(Long versionId, Long semesterId) {
+        if (versionId == null) {
+            return null;
+        }
+        if (scheduleVersionRepository == null) {
+            throw new IllegalStateException("Хранилище версий расписания недоступно");
+        }
+        ScheduleVersion version = scheduleVersionRepository.findByIdForUpdate(versionId)
+                .orElseThrow(() -> new NoSuchElementException("Версия расписания не найдена"));
+        if (!Objects.equals(version.getSemester().getId(), semesterId)) {
+            throw new IllegalArgumentException("Версия относится к другому семестру");
+        }
+        ensureEditableVersion(version);
+        return version;
+    }
+
+    private void ensureEditableVersion(ScheduleVersion version) {
+        if (version.getStatus() == ScheduleVersionStatus.ARCHIVED) {
+            throw new IllegalArgumentException(
+                    "Архивное расписание доступно только для просмотра; выберите опубликованное расписание или черновик"
+            );
+        }
+    }
+
+    private void ensureEditableRule(ScheduleRule rule) {
+        if (rule.getScheduleVersion() != null) {
+            ensureEditableVersion(rule.getScheduleVersion());
+        }
+    }
+
+    private void lockAndEnsureEditableRule(ScheduleRule rule) {
+        if (rule.getScheduleVersion() != null && scheduleVersionRepository != null) {
+            ScheduleVersion lockedVersion = scheduleVersionRepository
+                    .findByIdForUpdate(rule.getScheduleVersion().getId())
+                    .orElseThrow(() -> new NoSuchElementException("Версия расписания не найдена"));
+            rule.setScheduleVersion(lockedVersion);
+        }
+        ensureEditableRule(rule);
+    }
+
    private ScheduleRuleSlotDto toSlotDto(ScheduleRuleSlot slot) {
        TimeSlot timeSlot = slot.getTimeSlot();
        List<Subgroup> sortedSubgroups = sortedSubgroups(slot);
--- a/backend/src/main/java/com/magistr/app/service/ScheduleVersionService.java
+++ b/backend/src/main/java/com/magistr/app/service/ScheduleVersionService.java
@@ -0,0 +1,657 @@
+package com.magistr.app.service;
+
+import com.magistr.app.config.auth.AuthContext;
+import com.magistr.app.dto.RenderedLessonDto;
+import com.magistr.app.dto.ScheduleVersionCreateDto;
+import com.magistr.app.dto.ScheduleVersionDiffDto;
+import com.magistr.app.dto.ScheduleVersionDto;
+import com.magistr.app.dto.ScheduleVersionHistoryDto;
+import com.magistr.app.dto.ScheduleVersionValidationDto;
+import com.magistr.app.model.ScheduleRule;
+import com.magistr.app.model.ScheduleRuleSlot;
+import com.magistr.app.model.ScheduleVersion;
+import com.magistr.app.model.ScheduleVersionHistory;
+import com.magistr.app.model.ScheduleVersionStatus;
+import com.magistr.app.model.Semester;
+import com.magistr.app.model.StudentGroup;
+import com.magistr.app.model.Subgroup;
+import com.magistr.app.model.User;
+import com.magistr.app.repository.ScheduleRuleRepository;
+import com.magistr.app.repository.ScheduleVersionHistoryRepository;
+import com.magistr.app.repository.ScheduleVersionRepository;
+import com.magistr.app.repository.SemesterRepository;
+import com.magistr.app.repository.UserRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.DayOfWeek;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+@Service
+public class ScheduleVersionService {
+
+    private static final Logger log = LoggerFactory.getLogger(ScheduleVersionService.class);
+    private static final int MAX_RANGE_DAYS = 120;
+    private static final int MAX_REASON_LENGTH = 2000;
+
+    private final ScheduleVersionRepository versionRepository;
+    private final ScheduleVersionHistoryRepository historyRepository;
+    private final ScheduleRuleRepository ruleRepository;
+    private final SemesterRepository semesterRepository;
+    private final UserRepository userRepository;
+    private final ScheduleRuleService ruleService;
+    private final ScheduleGeneratorService generatorService;
+
+    public ScheduleVersionService(
+            ScheduleVersionRepository versionRepository,
+            ScheduleVersionHistoryRepository historyRepository,
+            ScheduleRuleRepository ruleRepository,
+            SemesterRepository semesterRepository,
+            UserRepository userRepository,
+            ScheduleRuleService ruleService,
+            ScheduleGeneratorService generatorService
+    ) {
+        this.versionRepository = versionRepository;
+        this.historyRepository = historyRepository;
+        this.ruleRepository = ruleRepository;
+        this.semesterRepository = semesterRepository;
+        this.userRepository = userRepository;
+        this.ruleService = ruleService;
+        this.generatorService = generatorService;
+    }
+
+    @Transactional(readOnly = true)
+    public List<ScheduleVersionDto> getVersions(Long semesterId) {
+        requireSemesterId(semesterId);
+        return versionRepository.findBySemesterIdWithDetails(semesterId).stream()
+                .map(this::toDto)
+                .toList();
+    }
+
+    @Transactional(readOnly = true)
+    public ScheduleVersionDto getVersion(Long versionId) {
+        return toDto(findVersion(versionId));
+    }
+
+    @Transactional(readOnly = true)
+    public List<ScheduleVersionHistoryDto> getHistory(Long semesterId) {
+        requireSemesterId(semesterId);
+        return historyRepository.findBySemesterIdWithDetails(semesterId).stream()
+                .map(this::toHistoryDto)
+                .toList();
+    }
+
+    @Transactional
+    public ScheduleVersionDto createDraft(ScheduleVersionCreateDto request) {
+        if (request == null || request.semesterId() == null) {
+            throw new IllegalArgumentException("Семестр для черновика обязателен");
+        }
+        Semester semester = semesterRepository.findByIdForUpdate(request.semesterId())
+                .orElseThrow(() -> new NoSuchElementException("Семестр не найден"));
+        List<ScheduleVersion> lockedVersions = versionRepository.findBySemesterIdForUpdate(semester.getId());
+        ScheduleVersion base = resolveBaseVersion(request.basedOnVersionId(), semester.getId(), lockedVersions);
+        int nextNumber = lockedVersions.stream()
+                .map(ScheduleVersion::getVersionNumber)
+                .filter(Objects::nonNull)
+                .max(Integer::compareTo)
+                .orElse(0) + 1;
+
+        ScheduleVersion draft = new ScheduleVersion();
+        draft.setSemester(semester);
+        draft.setVersionNumber(nextNumber);
+        draft.setName(normalizeName(request.name(), "Черновик версии " + nextNumber));
+        draft.setStatus(ScheduleVersionStatus.DRAFT);
+        draft.setBasedOnVersion(base);
+        draft.setCreatedBy(currentUser());
+        ScheduleVersion saved = versionRepository.saveAndFlush(draft);
+
+        if (base != null) {
+            cloneRules(base, saved);
+        }
+        addHistory(saved, "CREATED", currentUser(), base == null
+                ? "Создан пустой черновик"
+                : "Создан черновик на основе версии " + base.getVersionNumber());
+        log.info("Создан черновик расписания {} для семестра {} на основе версии {}",
+                saved.getId(), semester.getId(), base == null ? "без основы" : base.getId());
+        return toDto(findVersion(saved.getId()));
+    }
+
+    @Transactional(readOnly = true)
+    public ScheduleVersionValidationDto validate(Long versionId) {
+        ScheduleVersion version = findVersion(versionId);
+        List<ScheduleRule> rules = activeRules(versionId);
+        List<String> issues = ruleService.validateVersion(versionId);
+        long slotCount = rules.stream().mapToLong(rule -> rule.getSlots().size()).sum();
+        return new ScheduleVersionValidationDto(
+                version.getId(),
+                issues.isEmpty(),
+                rules.size(),
+                slotCount,
+                issues
+        );
+    }
+
+    @Transactional
+    public ScheduleVersionDto publish(Long versionId, String reason) {
+        ScheduleVersion target = lockVersion(versionId);
+        if (target.getStatus() != ScheduleVersionStatus.DRAFT) {
+            throw new IllegalArgumentException("Опубликовать можно только черновик");
+        }
+        String normalizedReason = requireReason(reason, "Для публикации укажите причину изменений");
+        ScheduleVersionValidationDto validation = validate(versionId);
+        if (!validation.valid()) {
+            throw new IllegalArgumentException(
+                    "Черновик не прошёл проверку: " + String.join("; ", validation.issues())
+            );
+        }
+
+        List<ScheduleVersion> versions = versionRepository
+                .findBySemesterIdForUpdate(target.getSemester().getId());
+        User actor = currentUser();
+        Instant now = Instant.now();
+        versions.stream()
+                .filter(version -> version.getStatus() == ScheduleVersionStatus.PUBLISHED)
+                .filter(version -> !Objects.equals(version.getId(), target.getId()))
+                .forEach(version -> archivePublished(version, actor, normalizedReason, now));
+        versionRepository.flush();
+
+        target.setStatus(ScheduleVersionStatus.PUBLISHED);
+        target.setChangeReason(normalizedReason);
+        target.setPublishedBy(actor);
+        target.setPublishedAt(now);
+        target.setArchivedAt(null);
+        versionRepository.saveAndFlush(target);
+        addHistory(target, "PUBLISHED", actor, normalizedReason);
+        generatorService.clearCache();
+        log.info("Опубликована версия расписания {} для семестра {}", target.getId(), target.getSemester().getId());
+        return toDto(findVersion(target.getId()));
+    }
+
+    @Transactional
+    public ScheduleVersionDto restore(Long versionId, String reason) {
+        ScheduleVersion target = lockVersion(versionId);
+        if (target.getStatus() != ScheduleVersionStatus.ARCHIVED || target.getPublishedAt() == null) {
+            throw new IllegalArgumentException("Восстановить можно только ранее опубликованную архивную версию");
+        }
+        String normalizedReason = requireReason(reason, "Для восстановления укажите причину");
+        List<ScheduleVersion> versions = versionRepository
+                .findBySemesterIdForUpdate(target.getSemester().getId());
+        ScheduleVersion current = versions.stream()
+                .filter(version -> version.getStatus() == ScheduleVersionStatus.PUBLISHED)
+                .findFirst()
+                .orElse(null);
+        User actor = currentUser();
+        Instant now = Instant.now();
+        if (current != null && !Objects.equals(current.getId(), target.getId())) {
+            archivePublished(current, actor, normalizedReason, now);
+            versionRepository.flush();
+        }
+
+        target.setStatus(ScheduleVersionStatus.PUBLISHED);
+        target.setChangeReason(normalizedReason);
+        target.setPublishedBy(actor);
+        target.setPublishedAt(now);
+        target.setArchivedAt(null);
+        target.setRestoredFromVersion(current);
+        versionRepository.saveAndFlush(target);
+        addHistory(target, "RESTORED", actor, normalizedReason);
+        generatorService.clearCache();
+        log.info("Восстановлена версия расписания {} для семестра {}", target.getId(), target.getSemester().getId());
+        return toDto(findVersion(target.getId()));
+    }
+
+    @Transactional(readOnly = true)
+    public ScheduleVersionDiffDto diff(Long targetVersionId, Long requestedBaseVersionId) {
+        ScheduleVersion target = findVersion(targetVersionId);
+        ScheduleVersion base = resolveDiffBase(target, requestedBaseVersionId);
+        List<ScheduleRule> beforeRules = activeRules(base.getId());
+        List<ScheduleRule> afterRules = activeRules(target.getId());
+
+        Map<Long, ScheduleRule> beforeByGroup = indexRulesByVersionGroup(beforeRules);
+        Map<Long, ScheduleRule> afterByGroup = indexRulesByVersionGroup(afterRules);
+        LinkedHashSet<Long> allGroups = new LinkedHashSet<>();
+        allGroups.addAll(beforeByGroup.keySet());
+        allGroups.addAll(afterByGroup.keySet());
+
+        int added = 0;
+        int removed = 0;
+        int changed = 0;
+        int unchanged = 0;
+        List<ScheduleVersionDiffDto.RuleChange> changes = new ArrayList<>();
+        for (Long groupId : allGroups) {
+            ScheduleRule before = beforeByGroup.get(groupId);
+            ScheduleRule after = afterByGroup.get(groupId);
+            String type;
+            if (before == null) {
+                type = "ADDED";
+                added++;
+            } else if (after == null) {
+                type = "REMOVED";
+                removed++;
+            } else if (!Objects.equals(ruleFingerprint(before), ruleFingerprint(after))) {
+                type = "CHANGED";
+                changed++;
+            } else {
+                unchanged++;
+                continue;
+            }
+            ScheduleRule representative = after == null ? before : after;
+            changes.add(new ScheduleVersionDiffDto.RuleChange(
+                    type,
+                    groupId,
+                    before == null ? null : before.getId(),
+                    after == null ? null : after.getId(),
+                    representative.getSubject().getName(),
+                    representative.getGroups().stream().map(StudentGroup::getName).sorted().toList(),
+                    before == null ? null : ruleSummary(before),
+                    after == null ? null : ruleSummary(after)
+            ));
+        }
+
+        LessonDifference lessons = compareLessons(base, target, beforeRules, afterRules);
+        return new ScheduleVersionDiffDto(
+                base.getId(),
+                versionLabel(base),
+                target.getId(),
+                versionLabel(target),
+                added,
+                removed,
+                changed,
+                unchanged,
+                lessons.added(),
+                lessons.removed(),
+                lessons.changed(),
+                changes.stream()
+                        .sorted(Comparator.comparing(ScheduleVersionDiffDto.RuleChange::subjectName))
+                        .toList()
+        );
+    }
+
+    private void cloneRules(ScheduleVersion base, ScheduleVersion target) {
+        List<ScheduleRule> sourceRules = activeRules(base.getId());
+        List<ScheduleRule> copies = new ArrayList<>();
+        for (ScheduleRule source : sourceRules) {
+            ScheduleRule copy = new ScheduleRule();
+            copy.setSubject(source.getSubject());
+            copy.setSemester(source.getSemester());
+            copy.setScheduleVersion(target);
+            copy.setVersionGroupId(source.getVersionGroupId() == null ? source.getId() : source.getVersionGroupId());
+            copy.setChangeReason(source.getChangeReason());
+            copy.setCreatedBy(currentUser());
+            copy.setStatus(source.getStatus());
+            copy.setValidFrom(source.getValidFrom());
+            copy.setValidTo(source.getValidTo());
+            copy.setLectureAcademicHours(source.getLectureAcademicHours());
+            copy.setLaboratoryAcademicHours(source.getLaboratoryAcademicHours());
+            copy.setPracticeAcademicHours(source.getPracticeAcademicHours());
+            copy.setLectureStartWeek(source.getLectureStartWeek());
+            copy.setLaboratoryStartWeek(source.getLaboratoryStartWeek());
+            copy.setPracticeStartWeek(source.getPracticeStartWeek());
+            copy.setGroups(new LinkedHashSet<>(source.getGroups()));
+
+            LinkedHashSet<ScheduleRuleSlot> copiedSlots = new LinkedHashSet<>();
+            for (ScheduleRuleSlot sourceSlot : source.getSlots()) {
+                ScheduleRuleSlot copySlot = new ScheduleRuleSlot();
+                copySlot.setScheduleRule(copy);
+                copySlot.setDayOfWeek(sourceSlot.getDayOfWeek());
+                copySlot.setParity(sourceSlot.getParity());
+                copySlot.setTimeSlot(sourceSlot.getTimeSlot());
+                copySlot.setSubgroups(new LinkedHashSet<>(sourceSlot.getSubgroups()));
+                copySlot.setTeacher(sourceSlot.getTeacher());
+                copySlot.setClassroom(sourceSlot.getClassroom());
+                copySlot.setLessonType(sourceSlot.getLessonType());
+                copySlot.setLessonFormat(sourceSlot.getLessonFormat());
+                copiedSlots.add(copySlot);
+            }
+            copy.setSlots(copiedSlots);
+            copies.add(copy);
+        }
+        ruleRepository.saveAllAndFlush(copies);
+    }
+
+    private void archivePublished(ScheduleVersion version, User actor, String reason, Instant archivedAt) {
+        version.setStatus(ScheduleVersionStatus.ARCHIVED);
+        version.setArchivedAt(archivedAt);
+        versionRepository.save(version);
+        addHistory(version, "ARCHIVED", actor, reason);
+    }
+
+    private void addHistory(ScheduleVersion version, String action, User actor, String reason) {
+        ScheduleVersionHistory history = new ScheduleVersionHistory();
+        history.setVersion(version);
+        history.setAction(action);
+        history.setActor(actor);
+        history.setReason(reason);
+        historyRepository.save(history);
+    }
+
+    private ScheduleVersion resolveBaseVersion(Long baseVersionId,
+                                               Long semesterId,
+                                               List<ScheduleVersion> versions) {
+        ScheduleVersion base = null;
+        if (baseVersionId != null) {
+            base = versions.stream()
+                    .filter(version -> Objects.equals(version.getId(), baseVersionId))
+                    .findFirst()
+                    .orElseThrow(() -> new IllegalArgumentException("Базовая версия относится к другому семестру"));
+        } else {
+            base = versions.stream()
+                    .filter(version -> version.getStatus() == ScheduleVersionStatus.PUBLISHED)
+                    .findFirst()
+                    .orElse(null);
+        }
+        if (base != null && !Objects.equals(base.getSemester().getId(), semesterId)) {
+            throw new IllegalArgumentException("Базовая версия относится к другому семестру");
+        }
+        return base;
+    }
+
+    private ScheduleVersion resolveDiffBase(ScheduleVersion target, Long requestedBaseVersionId) {
+        if (requestedBaseVersionId != null) {
+            ScheduleVersion base = findVersion(requestedBaseVersionId);
+            if (!Objects.equals(base.getSemester().getId(), target.getSemester().getId())) {
+                throw new IllegalArgumentException("Сравнивать можно только версии одного семестра");
+            }
+            return base;
+        }
+        if (target.getBasedOnVersion() != null) {
+            return findVersion(target.getBasedOnVersion().getId());
+        }
+        return versionRepository.findBySemesterIdWithDetails(target.getSemester().getId()).stream()
+                .filter(version -> version.getStatus() == ScheduleVersionStatus.PUBLISHED)
+                .filter(version -> !Objects.equals(version.getId(), target.getId()))
+                .findFirst()
+                .orElseThrow(() -> new IllegalArgumentException("Для этой версии нет базы сравнения"));
+    }
+
+    private LessonDifference compareLessons(ScheduleVersion base,
+                                            ScheduleVersion target,
+                                            List<ScheduleRule> beforeRules,
+                                            List<ScheduleRule> afterRules) {
+        List<RenderedLessonDto> beforeLessons = loadVersionLessons(base);
+        List<RenderedLessonDto> afterLessons = loadVersionLessons(target);
+        Map<Long, Long> beforeGroups = beforeRules.stream().collect(Collectors.toMap(
+                ScheduleRule::getId,
+                rule -> rule.getVersionGroupId() == null ? rule.getId() : rule.getVersionGroupId()
+        ));
+        Map<Long, Long> afterGroups = afterRules.stream().collect(Collectors.toMap(
+                ScheduleRule::getId,
+                rule -> rule.getVersionGroupId() == null ? rule.getId() : rule.getVersionGroupId()
+        ));
+        Map<LessonIdentity, List<String>> before = indexLessons(beforeLessons, beforeGroups);
+        Map<LessonIdentity, List<String>> after = indexLessons(afterLessons, afterGroups);
+        LinkedHashSet<LessonIdentity> keys = new LinkedHashSet<>();
+        keys.addAll(before.keySet());
+        keys.addAll(after.keySet());
+        int added = 0;
+        int removed = 0;
+        int changed = 0;
+        for (LessonIdentity key : keys) {
+            List<String> oldValues = new ArrayList<>(before.getOrDefault(key, List.of()));
+            List<String> newValues = new ArrayList<>(after.getOrDefault(key, List.of()));
+            for (int index = oldValues.size() - 1; index >= 0; index--) {
+                String value = oldValues.get(index);
+                int match = newValues.indexOf(value);
+                if (match >= 0) {
+                    oldValues.remove(index);
+                    newValues.remove(match);
+                }
+            }
+            int changedHere = Math.min(oldValues.size(), newValues.size());
+            changed += changedHere;
+            removed += oldValues.size() - changedHere;
+            added += newValues.size() - changedHere;
+        }
+        return new LessonDifference(added, removed, changed);
+    }
+
+    private Map<LessonIdentity, List<String>> indexLessons(List<RenderedLessonDto> lessons,
+                                                           Map<Long, Long> versionGroups) {
+        Map<String, RenderedLessonDto> unique = lessons.stream().collect(Collectors.toMap(
+                this::renderedLessonIdentity,
+                Function.identity(),
+                (first, ignored) -> first,
+                LinkedHashMap::new
+        ));
+        Map<LessonIdentity, List<String>> result = new LinkedHashMap<>();
+        for (RenderedLessonDto lesson : unique.values()) {
+            LessonIdentity identity = new LessonIdentity(
+                    versionGroups.getOrDefault(lesson.scheduleRuleId(), lesson.scheduleRuleId()),
+                    lesson.date(),
+                    lesson.lessonTypeId(),
+                    sortedIds(lesson.groupIds()),
+                    sortedIds(lesson.subgroupIds())
+            );
+            String value = List.of(
+                    Objects.toString(lesson.timeSlotId(), ""),
+                    Objects.toString(lesson.teacherId(), ""),
+                    Objects.toString(lesson.classroomId(), ""),
+                    Objects.toString(lesson.lessonFormat(), "")
+            ).toString();
+            result.computeIfAbsent(identity, ignored -> new ArrayList<>()).add(value);
+        }
+        result.values().forEach(values -> values.sort(String::compareTo));
+        return result;
+    }
+
+    private List<RenderedLessonDto> loadVersionLessons(ScheduleVersion version) {
+        List<RenderedLessonDto> lessons = new ArrayList<>();
+        LocalDate cursor = version.getSemester().getStartDate();
+        LocalDate semesterEnd = version.getSemester().getEndDate();
+        while (!cursor.isAfter(semesterEnd)) {
+            LocalDate chunkEnd = cursor.plusDays(MAX_RANGE_DAYS - 1L);
+            if (chunkEnd.isAfter(semesterEnd)) {
+                chunkEnd = semesterEnd;
+            }
+            lessons.addAll(generatorService.buildScheduleForVersion(version.getId(), cursor, chunkEnd));
+            cursor = chunkEnd.plusDays(1);
+        }
+        return lessons;
+    }
+
+    private String renderedLessonIdentity(RenderedLessonDto lesson) {
+        return List.of(
+                Objects.toString(lesson.scheduleRuleId(), ""),
+                Objects.toString(lesson.scheduleRuleSlotId(), ""),
+                Objects.toString(lesson.date(), ""),
+                sortedIds(lesson.groupIds()).toString(),
+                sortedIds(lesson.subgroupIds()).toString()
+        ).toString();
+    }
+
+    private Map<Long, ScheduleRule> indexRulesByVersionGroup(List<ScheduleRule> rules) {
+        return rules.stream().collect(Collectors.toMap(
+                rule -> rule.getVersionGroupId() == null ? rule.getId() : rule.getVersionGroupId(),
+                Function.identity(),
+                (first, ignored) -> first,
+                LinkedHashMap::new
+        ));
+    }
+
+    private String ruleFingerprint(ScheduleRule rule) {
+        List<String> slots = rule.getSlots().stream().map(this::slotFingerprint).sorted().toList();
+        return List.of(
+                rule.getSubject().getId(),
+                rule.getLectureAcademicHours(),
+                rule.getLaboratoryAcademicHours(),
+                rule.getPracticeAcademicHours(),
+                rule.getLectureStartWeek(),
+                rule.getLaboratoryStartWeek(),
+                rule.getPracticeStartWeek(),
+                rule.getGroups().stream().map(StudentGroup::getId).sorted().toList(),
+                slots
+        ).toString();
+    }
+
+    private String slotFingerprint(ScheduleRuleSlot slot) {
+        return List.of(
+                slot.getDayOfWeek(),
+                slot.getParity(),
+                slot.getTimeSlot().getId(),
+                slot.getTeacher().getId(),
+                slot.getClassroom().getId(),
+                slot.getLessonType().getId(),
+                slot.getLessonFormat(),
+                slot.getSubgroups().stream().map(Subgroup::getId).sorted().toList()
+        ).toString();
+    }
+
+    private String ruleSummary(ScheduleRule rule) {
+        String load = "лекции " + rule.getLectureAcademicHours()
+                + " ч., лабораторные " + rule.getLaboratoryAcademicHours()
+                + " ч., практики " + rule.getPracticeAcademicHours() + " ч.";
+        String slots = rule.getSlots().stream()
+                .sorted(Comparator
+                        .comparing(ScheduleRuleSlot::getDayOfWeek)
+                        .thenComparing(slot -> slot.getTimeSlot().getOrderNumber()))
+                .limit(4)
+                .map(slot -> ScheduleGeneratorService.dayName(DayOfWeek.of(slot.getDayOfWeek()))
+                        + ", " + slot.getTimeSlot().getOrderNumber() + " пара"
+                        + ", " + ScheduleGeneratorService.displayUserName(slot.getTeacher()))
+                .collect(Collectors.joining("; "));
+        return load + " · " + rule.getSlots().size() + " слотов" + (slots.isBlank() ? "" : ": " + slots);
+    }
+
+    private ScheduleVersionDto toDto(ScheduleVersion version) {
+        List<ScheduleRule> rules = activeRules(version.getId());
+        return new ScheduleVersionDto(
+                version.getId(),
+                version.getSemester().getId(),
+                semesterLabel(version.getSemester()),
+                version.getVersionNumber(),
+                version.getName(),
+                version.getStatus(),
+                idOf(version.getBasedOnVersion()),
+                idOf(version.getRestoredFromVersion()),
+                version.getChangeReason(),
+                idOf(version.getCreatedBy()),
+                nameOf(version.getCreatedBy()),
+                version.getCreatedAt(),
+                idOf(version.getPublishedBy()),
+                nameOf(version.getPublishedBy()),
+                version.getPublishedAt(),
+                version.getArchivedAt(),
+                rules.size(),
+                rules.stream().mapToLong(rule -> rule.getSlots().size()).sum()
+        );
+    }
+
+    private ScheduleVersionHistoryDto toHistoryDto(ScheduleVersionHistory history) {
+        return new ScheduleVersionHistoryDto(
+                history.getId(),
+                history.getVersion().getId(),
+                history.getVersion().getVersionNumber(),
+                history.getVersion().getName(),
+                history.getAction(),
+                idOf(history.getActor()),
+                nameOf(history.getActor()),
+                history.getReason(),
+                history.getCreatedAt()
+        );
+    }
+
+    private ScheduleVersion findVersion(Long versionId) {
+        if (versionId == null) {
+            throw new IllegalArgumentException("Версия расписания обязательна");
+        }
+        return versionRepository.findByIdWithDetails(versionId)
+                .orElseThrow(() -> new NoSuchElementException("Версия расписания не найдена"));
+    }
+
+    private ScheduleVersion lockVersion(Long versionId) {
+        if (versionId == null) {
+            throw new IllegalArgumentException("Версия расписания обязательна");
+        }
+        return versionRepository.findByIdForUpdate(versionId)
+                .orElseThrow(() -> new NoSuchElementException("Версия расписания не найдена"));
+    }
+
+    private List<ScheduleRule> activeRules(Long versionId) {
+        return ruleRepository.findActiveByVersionIdWithDetails(versionId, null);
+    }
+
+    private User currentUser() {
+        Long currentUserId = AuthContext.currentUserId();
+        return currentUserId == null ? null : userRepository.findById(currentUserId).orElse(null);
+    }
+
+    private String normalizeName(String name, String fallback) {
+        String normalized = name == null ? "" : name.trim();
+        if (normalized.isEmpty()) {
+            return fallback;
+        }
+        if (normalized.length() > 160) {
+            throw new IllegalArgumentException("Название версии не может быть длиннее 160 символов");
+        }
+        return normalized;
+    }
+
+    private String requireReason(String reason, String message) {
+        String normalized = reason == null ? "" : reason.trim();
+        if (normalized.isEmpty()) {
+            throw new IllegalArgumentException(message);
+        }
+        if (normalized.length() > MAX_REASON_LENGTH) {
+            throw new IllegalArgumentException("Причина не может быть длиннее 2000 символов");
+        }
+        return normalized;
+    }
+
+    private void requireSemesterId(Long semesterId) {
+        if (semesterId == null) {
+            throw new IllegalArgumentException("Семестр обязателен");
+        }
+    }
+
+    private String semesterLabel(Semester semester) {
+        return semester.getAcademicYear().getTitle() + " · "
+                + (semester.getSemesterType().name().equals("autumn") ? "осенний" : "весенний") + " семестр";
+    }
+
+    private String versionLabel(ScheduleVersion version) {
+        return "Версия " + version.getVersionNumber() + " · " + version.getName();
+    }
+
+    private Long idOf(ScheduleVersion version) {
+        return version == null ? null : version.getId();
+    }
+
+    private Long idOf(User user) {
+        return user == null ? null : user.getId();
+    }
+
+    private String nameOf(User user) {
+        return user == null ? null : ScheduleGeneratorService.displayUserName(user);
+    }
+
+    private List<Long> sortedIds(List<Long> ids) {
+        return ids == null ? List.of() : ids.stream().filter(Objects::nonNull).sorted().toList();
+    }
+
+    private record LessonIdentity(
+            Long versionGroupId,
+            LocalDate date,
+            Long lessonTypeId,
+            List<Long> groupIds,
+            List<Long> subgroupIds
+    ) {
+    }
+
+    private record LessonDifference(int added, int removed, int changed) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/service/TeacherAbsenceService.java
+++ b/backend/src/main/java/com/magistr/app/service/TeacherAbsenceService.java
@@ -0,0 +1,837 @@
+package com.magistr.app.service;
+
+import com.magistr.app.config.auth.AuthContext;
+import com.magistr.app.config.auth.AuthenticatedUser;
+import com.magistr.app.dto.RenderedLessonDto;
+import com.magistr.app.dto.ScheduleOverrideDto;
+import com.magistr.app.dto.TeacherAbsenceDto;
+import com.magistr.app.dto.TeacherAbsenceRequest;
+import com.magistr.app.dto.TeacherAbsenceResolutionRequest;
+import com.magistr.app.dto.TeacherAbsenceReviewRequest;
+import com.magistr.app.dto.TeacherAbsenceWizardDto;
+import com.magistr.app.model.Classroom;
+import com.magistr.app.model.LifecycleEntity;
+import com.magistr.app.model.Role;
+import com.magistr.app.model.ScheduleOverride;
+import com.magistr.app.model.ScheduleRuleSlot;
+import com.magistr.app.model.TeacherAbsence;
+import com.magistr.app.model.TeacherAbsenceDecision;
+import com.magistr.app.model.TimeSlot;
+import com.magistr.app.model.User;
+import com.magistr.app.repository.ClassroomRepository;
+import com.magistr.app.repository.ScheduleOverrideRepository;
+import com.magistr.app.repository.ScheduleRuleSlotRepository;
+import com.magistr.app.repository.TeacherAbsenceDecisionRepository;
+import com.magistr.app.repository.TeacherAbsenceRepository;
+import com.magistr.app.repository.TeacherDepartmentAssignmentRepository;
+import com.magistr.app.repository.TeacherSubjectRepository;
+import com.magistr.app.repository.TimeSlotRepository;
+import com.magistr.app.repository.UserRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+@Service
+public class TeacherAbsenceService {
+
+    private static final Logger log = LoggerFactory.getLogger(TeacherAbsenceService.class);
+    private static final Set<String> ACTIVE_ABSENCE_STATUSES = Set.of("PENDING", "APPROVED", "RESOLVED");
+    private static final Set<String> ALL_STATUSES = Set.of(
+            "PENDING", "APPROVED", "REJECTED", "RESOLVED", "CANCELLED"
+    );
+    private static final Set<String> RESOLUTIONS = Set.of(
+            "REPLACE_TEACHER", "MOVE_TIME", "CHANGE_CLASSROOM", "CANCEL", "REJECT"
+    );
+    private static final int MAX_RANGE_DAYS = 120;
+    private static final int MAX_DECISIONS = 100;
+    private static final int CANDIDATE_LIMIT = 5;
+
+    private final TeacherAbsenceRepository absenceRepository;
+    private final TeacherAbsenceDecisionRepository decisionRepository;
+    private final UserRepository userRepository;
+    private final TeacherSubjectRepository teacherSubjectRepository;
+    private final TeacherDepartmentAssignmentRepository assignmentRepository;
+    private final ClassroomRepository classroomRepository;
+    private final TimeSlotRepository timeSlotRepository;
+    private final ScheduleRuleSlotRepository scheduleRuleSlotRepository;
+    private final ScheduleOverrideRepository scheduleOverrideRepository;
+    private final ScheduleQueryService scheduleQueryService;
+    private final ScheduleOverrideService scheduleOverrideService;
+    private final BusinessTimeService businessTime;
+
+    public TeacherAbsenceService(
+            TeacherAbsenceRepository absenceRepository,
+            TeacherAbsenceDecisionRepository decisionRepository,
+            UserRepository userRepository,
+            TeacherSubjectRepository teacherSubjectRepository,
+            TeacherDepartmentAssignmentRepository assignmentRepository,
+            ClassroomRepository classroomRepository,
+            TimeSlotRepository timeSlotRepository,
+            ScheduleRuleSlotRepository scheduleRuleSlotRepository,
+            ScheduleOverrideRepository scheduleOverrideRepository,
+            ScheduleQueryService scheduleQueryService,
+            ScheduleOverrideService scheduleOverrideService,
+            BusinessTimeService businessTime
+    ) {
+        this.absenceRepository = absenceRepository;
+        this.decisionRepository = decisionRepository;
+        this.userRepository = userRepository;
+        this.teacherSubjectRepository = teacherSubjectRepository;
+        this.assignmentRepository = assignmentRepository;
+        this.classroomRepository = classroomRepository;
+        this.timeSlotRepository = timeSlotRepository;
+        this.scheduleRuleSlotRepository = scheduleRuleSlotRepository;
+        this.scheduleOverrideRepository = scheduleOverrideRepository;
+        this.scheduleQueryService = scheduleQueryService;
+        this.scheduleOverrideService = scheduleOverrideService;
+        this.businessTime = businessTime;
+    }
+
+    @Transactional(readOnly = true)
+    public List<TeacherAbsenceDto> getAll(String status) {
+        String normalizedStatus = cleanUpper(status);
+        if (normalizedStatus != null && !ALL_STATUSES.contains(normalizedStatus)) {
+            throw new IllegalArgumentException("Неизвестный статус отсутствия");
+        }
+        return absenceRepository.findAllWithTeacher().stream()
+                .filter(this::canView)
+                .filter(absence -> normalizedStatus == null || normalizedStatus.equals(absence.getStatus()))
+                .map(this::toDto)
+                .toList();
+    }
+
+    @Transactional
+    public TeacherAbsenceDto create(TeacherAbsenceRequest request) {
+        AuthenticatedUser current = currentUser();
+        if (request == null) {
+            throw new IllegalArgumentException("Передайте данные отсутствия преподавателя");
+        }
+        validateRange(request.startDate(), request.endDate());
+        String reason = clean(request.reason());
+        if (reason == null) {
+            throw new IllegalArgumentException("Причина отсутствия обязательна");
+        }
+        if (reason.length() > 2000) {
+            throw new IllegalArgumentException("Причина отсутствия не может превышать 2000 символов");
+        }
+
+        Long teacherId = current.role() == Role.TEACHER ? current.id() : request.teacherId();
+        if (teacherId == null) {
+            throw new IllegalArgumentException("Выберите преподавателя");
+        }
+        if (current.role() == Role.TEACHER
+                && request.teacherId() != null
+                && !Objects.equals(request.teacherId(), current.id())) {
+            throw forbidden("Преподаватель может зарегистрировать отсутствие только для себя");
+        }
+
+        User teacher = userRepository.findByIdForUpdate(teacherId)
+                .filter(user -> user.getRole() == Role.TEACHER)
+                .filter(user -> !user.isArchivedRecord())
+                .orElseThrow(() -> new IllegalArgumentException("Преподаватель не найден"));
+        ensureDepartmentScope(teacher, request.startDate(), request.endDate(), current);
+        if (absenceRepository.existsOverlapping(
+                teacherId,
+                ACTIVE_ABSENCE_STATUSES,
+                request.startDate(),
+                request.endDate()
+        )) {
+            throw new ScheduleConflictException(
+                    "Для преподавателя уже зарегистрировано отсутствие, пересекающееся с выбранным периодом"
+            );
+        }
+
+        var now = businessTime.now();
+        TeacherAbsence absence = new TeacherAbsence();
+        absence.setTeacher(teacher);
+        absence.setStartDate(request.startDate());
+        absence.setEndDate(request.endDate());
+        absence.setReason(reason);
+        absence.setRequestedBy(current.id());
+        absence.setCreatedAt(now);
+        absence.setUpdatedAt(now);
+        if (current.role() == Role.TEACHER) {
+            absence.setStatus("PENDING");
+        } else {
+            absence.setStatus("APPROVED");
+            absence.setReviewedBy(current.id());
+            absence.setReviewedAt(now);
+            absence.setReviewComment("Зарегистрировано ответственным сотрудником");
+        }
+        TeacherAbsence saved = absenceRepository.saveAndFlush(absence);
+        log.info(
+                "Зарегистрировано отсутствие преподавателя {} на период {}–{}, статус {}",
+                teacher.getId(),
+                request.startDate(),
+                request.endDate(),
+                saved.getStatus()
+        );
+        return toDto(saved);
+    }
+
+    @Transactional
+    public TeacherAbsenceDto review(Long id, TeacherAbsenceReviewRequest request) {
+        AuthenticatedUser current = currentUser();
+        if (current.role() == Role.TEACHER) {
+            throw forbidden("Преподаватель не может согласовывать собственное отсутствие");
+        }
+        if (request == null || request.approved() == null) {
+            throw new IllegalArgumentException("Укажите решение по заявке на отсутствие");
+        }
+        TeacherAbsence absence = getForUpdate(id);
+        ensureCanManage(absence, current);
+        if (!"PENDING".equals(absence.getStatus())) {
+            throw new IllegalArgumentException("Рассмотреть можно только отсутствие со статусом PENDING");
+        }
+        var now = businessTime.now();
+        absence.setStatus(Boolean.TRUE.equals(request.approved()) ? "APPROVED" : "REJECTED");
+        absence.setReviewedBy(current.id());
+        absence.setReviewedAt(now);
+        absence.setReviewComment(clean(request.comment()));
+        absence.setUpdatedAt(now);
+        TeacherAbsence saved = absenceRepository.saveAndFlush(absence);
+        log.info("Отсутствие {} переведено в статус {}", id, saved.getStatus());
+        return toDto(saved);
+    }
+
+    @Transactional
+    public TeacherAbsenceDto cancel(Long id) {
+        AuthenticatedUser current = currentUser();
+        TeacherAbsence absence = getForUpdate(id);
+        if (current.role() == Role.TEACHER) {
+            if (!Objects.equals(current.id(), absence.getTeacher().getId())) {
+                throw forbidden("Нельзя отменить отсутствие другого преподавателя");
+            }
+            if (!"PENDING".equals(absence.getStatus())) {
+                throw new IllegalArgumentException("Преподаватель может отменить только ожидающую заявку");
+            }
+        } else {
+            ensureCanManage(absence, current);
+            if (!Set.of("PENDING", "APPROVED").contains(absence.getStatus())) {
+                throw new IllegalArgumentException("Это отсутствие уже нельзя отменить");
+            }
+            if (decisionRepository.countByAbsenceId(id) > 0) {
+                throw new IllegalArgumentException("Нельзя отменить отсутствие после применения решений");
+            }
+        }
+        absence.setStatus("CANCELLED");
+        absence.setUpdatedAt(businessTime.now());
+        TeacherAbsence saved = absenceRepository.saveAndFlush(absence);
+        log.info("Отсутствие {} отменено", id);
+        return toDto(saved);
+    }
+
+    @Transactional(readOnly = true)
+    public TeacherAbsenceWizardDto getWizard(Long id) {
+        TeacherAbsence absence = getVisible(id);
+        List<TeacherAbsenceDecision> decisions = decisionRepository.findByAbsenceIdWithDetails(id);
+        Map<LessonKey, TeacherAbsenceDecision> decisionsByLesson = decisions.stream()
+                .collect(Collectors.toMap(
+                        decision -> new LessonKey(
+                                decision.getBaseRuleSlot().getId(),
+                                decision.getLessonDate()
+                        ),
+                        decision -> decision,
+                        (first, second) -> second,
+                        LinkedHashMap::new
+                ));
+        List<RenderedLessonDto> lessons = affectedLessons(absence);
+        List<TeacherAbsenceWizardDto.AffectedLesson> affected = lessons.stream()
+                .map(lesson -> toAffectedLesson(
+                        absence,
+                        lesson,
+                        decisionsByLesson.get(new LessonKey(lesson.scheduleRuleSlotId(), lesson.date()))
+                ))
+                .toList();
+        return new TeacherAbsenceWizardDto(
+                toDto(absence),
+                affected,
+                decisions.stream().map(this::toDecisionLog).toList()
+        );
+    }
+
+    @Transactional
+    public TeacherAbsenceWizardDto resolve(Long id, TeacherAbsenceResolutionRequest request) {
+        AuthenticatedUser current = currentUser();
+        if (current.role() == Role.TEACHER) {
+            throw forbidden("Преподаватель не может применять решения мастера замены");
+        }
+        TeacherAbsence absence = getForUpdate(id);
+        ensureCanManage(absence, current);
+        if (!"APPROVED".equals(absence.getStatus())) {
+            throw new IllegalArgumentException("Мастер замены доступен только для согласованного отсутствия");
+        }
+
+        List<TeacherAbsenceResolutionRequest.Decision> requested = request == null
+                || request.decisions() == null
+                ? List.of()
+                : request.decisions();
+        if (requested.size() > MAX_DECISIONS) {
+            throw new IllegalArgumentException("За один раз можно обработать не более 100 занятий");
+        }
+
+        Map<LessonKey, RenderedLessonDto> affectedByKey = affectedLessons(absence).stream()
+                .collect(Collectors.toMap(
+                        lesson -> new LessonKey(lesson.scheduleRuleSlotId(), lesson.date()),
+                        lesson -> lesson,
+                        (first, second) -> first,
+                        LinkedHashMap::new
+                ));
+        Set<LessonKey> processedKeys = decisionRepository.findByAbsenceIdWithDetails(id).stream()
+                .map(decision -> new LessonKey(
+                        decision.getBaseRuleSlot().getId(),
+                        decision.getLessonDate()
+                ))
+                .collect(Collectors.toCollection(LinkedHashSet::new));
+        if (affectedByKey.isEmpty() && requested.isEmpty()) {
+            absence.setStatus("RESOLVED");
+            absence.setUpdatedAt(businessTime.now());
+            absenceRepository.saveAndFlush(absence);
+            return getWizard(id);
+        }
+        if (requested.isEmpty()) {
+            throw new IllegalArgumentException("Выберите хотя бы одно решение");
+        }
+
+        Set<LessonKey> requestKeys = new LinkedHashSet<>();
+        for (TeacherAbsenceResolutionRequest.Decision item : requested) {
+            validateDecisionKey(item);
+            LessonKey key = new LessonKey(item.baseRuleSlotId(), item.lessonDate());
+            if (!requestKeys.add(key)) {
+                throw new IllegalArgumentException("Одно занятие нельзя обработать дважды");
+            }
+            RenderedLessonDto lesson = affectedByKey.get(key);
+            if (lesson == null) {
+                throw new IllegalArgumentException("Занятие не относится к выбранному отсутствию");
+            }
+            if (processedKeys.contains(key)) {
+                throw new ScheduleConflictException("Для занятия решение уже зафиксировано в журнале");
+            }
+            applyDecision(absence, lesson, item, current.id());
+            processedKeys.add(key);
+        }
+
+        if (affectedByKey.keySet().stream().allMatch(processedKeys::contains)) {
+            absence.setStatus("RESOLVED");
+        }
+        absence.setUpdatedAt(businessTime.now());
+        absenceRepository.saveAndFlush(absence);
+        log.info(
+                "Для отсутствия {} обработано {} занятий, итоговый статус {}",
+                id,
+                requested.size(),
+                absence.getStatus()
+        );
+        return getWizard(id);
+    }
+
+    private void applyDecision(
+            TeacherAbsence absence,
+            RenderedLessonDto lesson,
+            TeacherAbsenceResolutionRequest.Decision request,
+            Long userId
+    ) {
+        String resolution = cleanUpper(request.resolution());
+        if (resolution == null || !RESOLUTIONS.contains(resolution)) {
+            throw new IllegalArgumentException("Неизвестный способ разрешения занятия");
+        }
+        if (lesson.scheduleOverrideId() != null && !"REJECT".equals(resolution)) {
+            throw new ScheduleConflictException(
+                    "У занятия уже есть точечное изменение; откройте его в реестре или отклоните предложение"
+            );
+        }
+
+        ScheduleOverride savedOverride = null;
+        if (!"REJECT".equals(resolution)) {
+            ScheduleOverrideDto overrideRequest = buildOverrideRequest(absence, lesson, request, resolution);
+            validateQualifiedReplacement(absence, lesson, overrideRequest, resolution);
+            ScheduleOverrideDto saved = scheduleOverrideService.create(overrideRequest);
+            savedOverride = scheduleOverrideRepository.findById(saved.id())
+                    .orElseThrow(() -> new IllegalStateException(
+                            "Созданное точечное изменение не найдено для записи в журнал"
+                    ));
+        }
+
+        ScheduleRuleSlot baseSlot = scheduleRuleSlotRepository.findById(request.baseRuleSlotId())
+                .orElseThrow(() -> new IllegalArgumentException("Базовый слот расписания не найден"));
+        TeacherAbsenceDecision decision = new TeacherAbsenceDecision();
+        decision.setAbsence(absence);
+        decision.setBaseRuleSlot(baseSlot);
+        decision.setLessonDate(request.lessonDate());
+        decision.setResolution(resolution);
+        decision.setDecisionStatus("REJECT".equals(resolution) ? "REJECTED" : "APPLIED");
+        decision.setScheduleOverride(savedOverride);
+        decision.setComment(clean(request.comment()));
+        decision.setDecidedBy(userId);
+        decision.setDecidedAt(businessTime.now());
+        decisionRepository.saveAndFlush(decision);
+    }
+
+    private ScheduleOverrideDto buildOverrideRequest(
+            TeacherAbsence absence,
+            RenderedLessonDto lesson,
+            TeacherAbsenceResolutionRequest.Decision request,
+            String resolution
+    ) {
+        String action;
+        LocalDate targetDate = null;
+        Long timeSlotId = null;
+        Long classroomId = null;
+        Long teacherId = null;
+        switch (resolution) {
+            case "REPLACE_TEACHER" -> {
+                action = "REPLACE";
+                teacherId = required(request.newTeacherId(), "Выберите преподавателя для замены");
+                classroomId = request.newClassroomId();
+            }
+            case "CHANGE_CLASSROOM" -> {
+                action = "REPLACE";
+                classroomId = required(request.newClassroomId(), "Выберите новую аудиторию");
+            }
+            case "MOVE_TIME" -> {
+                action = "MOVE";
+                timeSlotId = required(request.newTimeSlotId(), "Выберите новое время занятия");
+                targetDate = request.targetLessonDate();
+                classroomId = request.newClassroomId();
+                if (targetDate == null
+                        || (!targetDate.isBefore(absence.getStartDate())
+                        && !targetDate.isAfter(absence.getEndDate()))) {
+                    throw new IllegalArgumentException(
+                            "Перенесите занятие на дату вне периода отсутствия преподавателя"
+                    );
+                }
+            }
+            case "CANCEL" -> action = "CANCEL";
+            default -> throw new IllegalArgumentException("Неизвестный способ разрешения занятия");
+        }
+        return new ScheduleOverrideDto(
+                null,
+                lesson.scheduleRuleSlotId(),
+                lesson.date(),
+                targetDate,
+                action,
+                timeSlotId,
+                classroomId,
+                teacherId,
+                null,
+                "Отсутствие №" + absence.getId() + ": " + absence.getReason(),
+                null,
+                null
+        );
+    }
+
+    private void validateQualifiedReplacement(
+            TeacherAbsence absence,
+            RenderedLessonDto lesson,
+            ScheduleOverrideDto override,
+            String resolution
+    ) {
+        if (!"REPLACE_TEACHER".equals(resolution)) {
+            return;
+        }
+        Long teacherId = override.newTeacherId();
+        List<Long> qualifiedIds = qualifiedTeacherIds(lesson);
+        if (!qualifiedIds.contains(teacherId)) {
+            throw new IllegalArgumentException(
+                    "Выбранный преподаватель не подтверждён для дисциплины и типа занятия"
+            );
+        }
+        User replacement = userRepository.findById(teacherId)
+                .filter(user -> user.getRole() == Role.TEACHER)
+                .filter(user -> user.isActiveOn(lesson.date()))
+                .orElseThrow(() -> new IllegalArgumentException("Активный преподаватель для замены не найден"));
+        if (Objects.equals(replacement.getId(), absence.getTeacher().getId())
+                || absenceRepository.isTeacherAbsentOn(replacement.getId(), lesson.date())) {
+            throw new IllegalArgumentException("Выбранный преподаватель отсутствует в дату занятия");
+        }
+    }
+
+    private TeacherAbsenceWizardDto.AffectedLesson toAffectedLesson(
+            TeacherAbsence absence,
+            RenderedLessonDto lesson,
+            TeacherAbsenceDecision decision
+    ) {
+        AuthenticatedUser current = currentUser();
+        boolean canSuggest = "APPROVED".equals(absence.getStatus())
+                && current.role() != Role.TEACHER
+                && decision == null
+                && lesson.scheduleOverrideId() == null;
+        return new TeacherAbsenceWizardDto.AffectedLesson(
+                lesson.scheduleRuleSlotId(),
+                lesson.date(),
+                lesson.startTime(),
+                lesson.endTime(),
+                lesson.subjectId(),
+                lesson.subjectName(),
+                lesson.lessonTypeId(),
+                lesson.lessonTypeName(),
+                lesson.classroomId(),
+                lesson.classroomName(),
+                lesson.groupNames() == null ? List.of() : lesson.groupNames(),
+                lesson.scheduleOverrideId(),
+                decision == null ? null : decision.getDecisionStatus(),
+                canSuggest ? teacherCandidates(absence, lesson) : List.of(),
+                canSuggest ? moveCandidates(absence, lesson) : List.of(),
+                canSuggest ? classroomCandidates(absence, lesson) : List.of(),
+                decision == null
+        );
+    }
+
+    private List<TeacherAbsenceWizardDto.Candidate> teacherCandidates(
+            TeacherAbsence absence,
+            RenderedLessonDto lesson
+    ) {
+        List<Long> ids = qualifiedTeacherIds(lesson);
+        if (ids.isEmpty()) {
+            return List.of();
+        }
+        return userRepository.findAllById(ids).stream()
+                .filter(user -> user.getRole() == Role.TEACHER)
+                .filter(user -> user.isActiveOn(lesson.date()))
+                .filter(user -> !Objects.equals(user.getId(), absence.getTeacher().getId()))
+                .filter(user -> !absenceRepository.isTeacherAbsentOn(user.getId(), lesson.date()))
+                .sorted(Comparator.comparing(User::getFullName, Comparator.nullsLast(String::compareTo)))
+                .filter(user -> candidateIsValid(new ScheduleOverrideDto(
+                        null,
+                        lesson.scheduleRuleSlotId(),
+                        lesson.date(),
+                        "REPLACE",
+                        null,
+                        null,
+                        user.getId(),
+                        null,
+                        "Предпросмотр замены преподавателя",
+                        null,
+                        null
+                )))
+                .limit(CANDIDATE_LIMIT)
+                .map(user -> new TeacherAbsenceWizardDto.Candidate(
+                        user.getId(),
+                        displayName(user),
+                        user.getJobTitle()
+                ))
+                .toList();
+    }
+
+    private List<Long> qualifiedTeacherIds(RenderedLessonDto lesson) {
+        if (lesson.subjectId() == null || lesson.lessonTypeId() == null) {
+            return List.of();
+        }
+        return teacherSubjectRepository.findQualifiedTeacherIds(
+                lesson.subjectId(),
+                lesson.lessonTypeId()
+        );
+    }
+
+    private List<TeacherAbsenceWizardDto.MoveCandidate> moveCandidates(
+            TeacherAbsence absence,
+            RenderedLessonDto lesson
+    ) {
+        List<LocalDate> dates;
+        try {
+            dates = scheduleOverrideService.getAvailability(
+                    lesson.scheduleRuleSlotId(),
+                    lesson.date()
+            ).availableDates();
+        } catch (RuntimeException exception) {
+            log.debug(
+                    "Не удалось построить даты переноса для слота {}: {}",
+                    lesson.scheduleRuleSlotId(),
+                    exception.getMessage()
+            );
+            return List.of();
+        }
+        List<LocalDate> nearestDates = dates.stream()
+                .filter(date -> date.isBefore(absence.getStartDate()) || date.isAfter(absence.getEndDate()))
+                .sorted(Comparator
+                        .comparingLong((LocalDate date) -> Math.abs(ChronoUnit.DAYS.between(lesson.date(), date)))
+                        .thenComparing(LocalDate::compareTo))
+                .limit(7)
+                .toList();
+        List<TimeSlot> slots = timeSlotRepository.findAllForSchedule();
+        List<TeacherAbsenceWizardDto.MoveCandidate> result = new ArrayList<>();
+        for (LocalDate date : nearestDates) {
+            for (TimeSlot slot : slots) {
+                if (candidateIsValid(new ScheduleOverrideDto(
+                        null,
+                        lesson.scheduleRuleSlotId(),
+                        lesson.date(),
+                        date,
+                        "MOVE",
+                        slot.getId(),
+                        null,
+                        null,
+                        null,
+                        "Предпросмотр переноса из-за отсутствия преподавателя",
+                        null,
+                        null
+                ))) {
+                    result.add(new TeacherAbsenceWizardDto.MoveCandidate(
+                            date,
+                            slot.getId(),
+                            slot.getOrderNumber(),
+                            slot.getStartTime(),
+                            slot.getEndTime(),
+                            "Ближайшее допустимое время"
+                    ));
+                    if (result.size() >= CANDIDATE_LIMIT) {
+                        return result;
+                    }
+                }
+            }
+        }
+        return result;
+    }
+
+    private List<TeacherAbsenceWizardDto.Candidate> classroomCandidates(
+            TeacherAbsence absence,
+            RenderedLessonDto lesson
+    ) {
+        return classroomRepository.findByStatusNot(LifecycleEntity.STATUS_ARCHIVED).stream()
+                .filter(classroom -> !Objects.equals(classroom.getId(), lesson.classroomId()))
+                .filter(classroom -> Boolean.TRUE.equals(classroom.getIsAvailable()))
+                .filter(classroom -> classroom.isActiveOn(lesson.date()))
+                .sorted(Comparator.comparing(Classroom::getName, Comparator.nullsLast(String::compareTo)))
+                .filter(classroom -> candidateIsValid(new ScheduleOverrideDto(
+                        null,
+                        lesson.scheduleRuleSlotId(),
+                        lesson.date(),
+                        "REPLACE",
+                        null,
+                        classroom.getId(),
+                        null,
+                        null,
+                        "Предпросмотр замены аудитории",
+                        null,
+                        null
+                )))
+                .limit(CANDIDATE_LIMIT)
+                .map(classroom -> new TeacherAbsenceWizardDto.Candidate(
+                        classroom.getId(),
+                        classroom.getName(),
+                        classroom.getBuilding()
+                ))
+                .toList();
+    }
+
+    private boolean candidateIsValid(ScheduleOverrideDto request) {
+        try {
+            scheduleOverrideService.validateCandidate(request);
+            return true;
+        } catch (RuntimeException exception) {
+            return false;
+        }
+    }
+
+    private List<RenderedLessonDto> affectedLessons(TeacherAbsence absence) {
+        return scheduleQueryService.search(
+                        null,
+                        absence.getTeacher().getId(),
+                        null,
+                        null,
+                        null,
+                        null,
+                        null,
+                        null,
+                        absence.getStartDate(),
+                        absence.getEndDate()
+                ).stream()
+                .filter(lesson -> lesson.scheduleRuleSlotId() != null)
+                .sorted(Comparator
+                        .comparing(RenderedLessonDto::date)
+                        .thenComparing(
+                                RenderedLessonDto::startTime,
+                                Comparator.nullsLast(Comparator.naturalOrder())
+                        )
+                        .thenComparing(
+                                RenderedLessonDto::subjectName,
+                                Comparator.nullsLast(String::compareTo)
+                        ))
+                .toList();
+    }
+
+    private TeacherAbsence getVisible(Long id) {
+        TeacherAbsence absence = absenceRepository.findByIdWithTeacher(id)
+                .orElseThrow(() -> notFound(id));
+        if (!canView(absence)) {
+            throw forbidden("Недостаточно прав для просмотра отсутствия");
+        }
+        return absence;
+    }
+
+    private TeacherAbsence getForUpdate(Long id) {
+        return absenceRepository.findByIdForUpdate(id)
+                .orElseThrow(() -> notFound(id));
+    }
+
+    private boolean canView(TeacherAbsence absence) {
+        AuthenticatedUser current = currentUser();
+        if (current.role() == Role.ADMIN || current.role() == Role.EDUCATION_OFFICE) {
+            return true;
+        }
+        if (current.role() == Role.TEACHER) {
+            return Objects.equals(current.id(), absence.getTeacher().getId());
+        }
+        return current.role() == Role.DEPARTMENT
+                && belongsToDepartment(absence, current.departmentId());
+    }
+
+    private void ensureCanManage(TeacherAbsence absence, AuthenticatedUser current) {
+        if (current.role() == Role.ADMIN || current.role() == Role.EDUCATION_OFFICE) {
+            return;
+        }
+        if (current.role() == Role.DEPARTMENT && belongsToDepartment(absence, current.departmentId())) {
+            return;
+        }
+        throw forbidden("Недостаточно прав для изменения отсутствия");
+    }
+
+    private void ensureDepartmentScope(
+            User teacher,
+            LocalDate startDate,
+            LocalDate endDate,
+            AuthenticatedUser current
+    ) {
+        if (current.role() != Role.DEPARTMENT) {
+            return;
+        }
+        if (current.departmentId() == null
+                || assignmentRepository.findForTeachersBetween(
+                        Set.of(teacher.getId()),
+                        startDate,
+                        endDate
+                ).stream().noneMatch(assignment -> Objects.equals(
+                        assignment.getDepartment().getId(),
+                        current.departmentId()
+                ))) {
+            throw forbidden("Кафедра может регистрировать отсутствие только своего преподавателя");
+        }
+    }
+
+    private boolean belongsToDepartment(TeacherAbsence absence, Long departmentId) {
+        return departmentId != null
+                && assignmentRepository.findForTeachersBetween(
+                        Set.of(absence.getTeacher().getId()),
+                        absence.getStartDate(),
+                        absence.getEndDate()
+                ).stream().anyMatch(assignment -> Objects.equals(
+                        assignment.getDepartment().getId(),
+                        departmentId
+                ));
+    }
+
+    private TeacherAbsenceDto toDto(TeacherAbsence absence) {
+        User teacher = absence.getTeacher();
+        return new TeacherAbsenceDto(
+                absence.getId(),
+                teacher == null ? null : teacher.getId(),
+                teacher == null ? null : displayName(teacher),
+                teacher == null ? null : teacher.getDepartmentId(),
+                absence.getStartDate(),
+                absence.getEndDate(),
+                absence.getReason(),
+                absence.getStatus(),
+                absence.getRequestedBy(),
+                absence.getReviewedBy(),
+                absence.getReviewComment(),
+                absence.getReviewedAt(),
+                absence.getCreatedAt(),
+                absence.getUpdatedAt(),
+                absence.getId() == null ? 0 : decisionRepository.countByAbsenceId(absence.getId())
+        );
+    }
+
+    private TeacherAbsenceWizardDto.DecisionLog toDecisionLog(TeacherAbsenceDecision decision) {
+        return new TeacherAbsenceWizardDto.DecisionLog(
+                decision.getId(),
+                decision.getBaseRuleSlot().getId(),
+                decision.getLessonDate(),
+                decision.getResolution(),
+                decision.getDecisionStatus(),
+                decision.getScheduleOverride() == null ? null : decision.getScheduleOverride().getId(),
+                decision.getComment(),
+                decision.getDecidedBy(),
+                decision.getDecidedAt()
+        );
+    }
+
+    private void validateRange(LocalDate startDate, LocalDate endDate) {
+        if (startDate == null || endDate == null) {
+            throw new IllegalArgumentException("Дата начала и дата окончания отсутствия обязательны");
+        }
+        if (endDate.isBefore(startDate)) {
+            throw new IllegalArgumentException("Дата окончания отсутствия не может быть раньше даты начала");
+        }
+        if (ChronoUnit.DAYS.between(startDate, endDate) + 1 > MAX_RANGE_DAYS) {
+            throw new IllegalArgumentException("Период одного отсутствия не может превышать 120 дней");
+        }
+    }
+
+    private void validateDecisionKey(TeacherAbsenceResolutionRequest.Decision decision) {
+        if (decision == null || decision.baseRuleSlotId() == null || decision.lessonDate() == null) {
+            throw new IllegalArgumentException("Для решения укажите занятие и исходную дату");
+        }
+    }
+
+    private AuthenticatedUser currentUser() {
+        AuthenticatedUser current = AuthContext.getCurrentUser();
+        if (current == null) {
+            throw new ResponseStatusException(HttpStatus.UNAUTHORIZED, "Не удалось определить пользователя");
+        }
+        return current;
+    }
+
+    private ResponseStatusException forbidden(String message) {
+        return new ResponseStatusException(HttpStatus.FORBIDDEN, message);
+    }
+
+    private NoSuchElementException notFound(Long id) {
+        return new NoSuchElementException("Отсутствие преподавателя с идентификатором " + id + " не найдено");
+    }
+
+    private <T> T required(T value, String message) {
+        if (value == null) {
+            throw new IllegalArgumentException(message);
+        }
+        return value;
+    }
+
+    private String clean(String value) {
+        return value == null || value.isBlank() ? null : value.trim();
+    }
+
+    private String cleanUpper(String value) {
+        String cleaned = clean(value);
+        return cleaned == null ? null : cleaned.toUpperCase(Locale.ROOT);
+    }
+
+    private String displayName(User user) {
+        if (user == null) {
+            return "Преподаватель не указан";
+        }
+        if (user.getFullName() != null && !user.getFullName().isBlank()) {
+            return user.getFullName();
+        }
+        return user.getUsername();
+    }
+
+    private record LessonKey(Long baseRuleSlotId, LocalDate lessonDate) {
+    }
+}
--- a/backend/src/main/java/com/magistr/app/service/TeacherAvailabilityPolicyService.java
+++ b/backend/src/main/java/com/magistr/app/service/TeacherAvailabilityPolicyService.java
@@ -0,0 +1,106 @@
+package com.magistr.app.service;
+
+import com.magistr.app.model.Semester;
+import com.magistr.app.model.TeacherPreference;
+import com.magistr.app.model.TimeSlot;
+import com.magistr.app.repository.TeacherPreferenceRepository;
+import com.magistr.app.repository.TimeSlotRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+
+@Service
+public class TeacherAvailabilityPolicyService {
+
+    private final TeacherPreferenceRepository preferenceRepository;
+    private final TimeSlotRepository timeSlotRepository;
+
+    public TeacherAvailabilityPolicyService(
+            TeacherPreferenceRepository preferenceRepository,
+            TimeSlotRepository timeSlotRepository
+    ) {
+        this.preferenceRepository = preferenceRepository;
+        this.timeSlotRepository = timeSlotRepository;
+    }
+
+    @Transactional(readOnly = true)
+    public void assertLessonAvailable(Long teacherId, Long semesterId, LocalDate date, Long timeSlotId) {
+        if (teacherId == null || semesterId == null || date == null || timeSlotId == null) return;
+        TimeSlot candidateSlot = timeSlotRepository.findById(timeSlotId)
+                .orElseThrow(() -> new IllegalArgumentException("Временной слот не найден"));
+        List<TeacherPreference> constraints = preferenceRepository
+                .findApprovedForTeacherAndSemester(teacherId, semesterId);
+        TeacherPreference conflict = constraints.stream()
+                .filter(this::isHard)
+                .filter(preference -> conflicts(preference, date, candidateSlot))
+                .findFirst()
+                .orElse(null);
+        if (conflict != null) {
+            throw new ScheduleConflictException(conflict.getPreferenceDate() == null
+                    ? "Преподаватель отметил строгую недоступность в выбранный день и время"
+                    : "Преподаватель отметил полную недоступность на выбранную дату");
+        }
+    }
+
+    @Transactional(readOnly = true)
+    public void assertRuleSlotAvailable(
+            Long teacherId,
+            Semester semester,
+            Integer dayOfWeek,
+            Long timeSlotId,
+            Set<Integer> activeWeeks
+    ) {
+        if (teacherId == null || semester == null || dayOfWeek == null || timeSlotId == null) return;
+        TimeSlot candidateSlot = timeSlotRepository.findById(timeSlotId)
+                .orElseThrow(() -> new IllegalArgumentException("Временной слот не найден"));
+        List<TeacherPreference> constraints = preferenceRepository
+                .findApprovedForTeacherAndSemester(teacherId, semester.getId());
+        for (TeacherPreference preference : constraints) {
+            if (!isHard(preference)) continue;
+            if (preference.getPreferenceDate() == null) {
+                if (Objects.equals(preference.getDayOfWeek(), dayOfWeek)
+                        && sameOrder(preference.getTimeSlot(), candidateSlot)) {
+                    throw unavailableRuleConflict();
+                }
+                continue;
+            }
+            LocalDate date = preference.getPreferenceDate();
+            if (date.getDayOfWeek().getValue() != dayOfWeek) continue;
+            int week = Math.toIntExact(ChronoUnit.DAYS.between(semester.getStartDate(), date) / 7 + 1);
+            if (activeWeeks == null || activeWeeks.contains(week)) {
+                throw unavailableRuleConflict();
+            }
+        }
+    }
+
+    private ScheduleRuleConflictException unavailableRuleConflict() {
+        return new ScheduleRuleConflictException(
+                "Невозможно сохранить правило: преподаватель строго недоступен в одном из выбранных интервалов",
+                null,
+                List.of("teacherAvailability"),
+                List.of("Строгая недоступность преподавателя")
+        );
+    }
+
+    private boolean conflicts(TeacherPreference preference, LocalDate date, TimeSlot candidateSlot) {
+        if (preference.getPreferenceDate() != null) {
+            return Objects.equals(preference.getPreferenceDate(), date);
+        }
+        return Objects.equals(preference.getDayOfWeek(), date.getDayOfWeek().getValue())
+                && sameOrder(preference.getTimeSlot(), candidateSlot);
+    }
+
+    private boolean sameOrder(TimeSlot first, TimeSlot second) {
+        return first != null && second != null && Objects.equals(first.getOrderNumber(), second.getOrderNumber());
+    }
+
+    private boolean isHard(TeacherPreference preference) {
+        return "APPROVED".equals(preference.getStatus())
+                && "HARD_UNAVAILABLE".equals(preference.getPreferenceType());
+    }
+}
--- a/backend/src/main/java/com/magistr/app/service/TeacherChangeRequestService.java
+++ b/backend/src/main/java/com/magistr/app/service/TeacherChangeRequestService.java
@@ -0,0 +1,493 @@
+package com.magistr.app.service;
+
+import com.magistr.app.config.auth.AuthContext;
+import com.magistr.app.config.auth.AuthenticatedUser;
+import com.magistr.app.dto.RenderedLessonDto;
+import com.magistr.app.dto.ScheduleOverrideDto;
+import com.magistr.app.dto.TeacherChangeCandidatesDto;
+import com.magistr.app.dto.TeacherChangeRequestDto;
+import com.magistr.app.dto.TeacherChangeRequestPayload;
+import com.magistr.app.dto.TeacherChangeReviewRequest;
+import com.magistr.app.model.Classroom;
+import com.magistr.app.model.Role;
+import com.magistr.app.model.ScheduleOverride;
+import com.magistr.app.model.ScheduleRuleSlot;
+import com.magistr.app.model.TeacherChangeRequest;
+import com.magistr.app.model.TeacherChangeRequestHistory;
+import com.magistr.app.model.TimeSlot;
+import com.magistr.app.repository.ClassroomRepository;
+import com.magistr.app.repository.ScheduleOverrideRepository;
+import com.magistr.app.repository.ScheduleRuleSlotRepository;
+import com.magistr.app.repository.TeacherChangeRequestHistoryRepository;
+import com.magistr.app.repository.TeacherChangeRequestRepository;
+import com.magistr.app.repository.TeacherDepartmentAssignmentRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.time.LocalDate;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Locale;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.Set;
+
+@Service
+public class TeacherChangeRequestService {
+
+    private static final Logger log = LoggerFactory.getLogger(TeacherChangeRequestService.class);
+    private static final Set<String> TYPES = Set.of("MOVE", "CHANGE_CLASSROOM", "CANCEL");
+    private static final Set<String> STATUSES = Set.of("PENDING", "APPROVED", "REJECTED", "CANCELLED");
+
+    private final TeacherChangeRequestRepository requestRepository;
+    private final TeacherChangeRequestHistoryRepository historyRepository;
+    private final ScheduleRuleSlotRepository ruleSlotRepository;
+    private final ScheduleOverrideRepository overrideRepository;
+    private final ClassroomRepository classroomRepository;
+    private final TeacherDepartmentAssignmentRepository assignmentRepository;
+    private final ScheduleQueryService scheduleQueryService;
+    private final ScheduleOverrideService scheduleOverrideService;
+    private final EffectiveTimeSlotService effectiveTimeSlotService;
+    private final BusinessTimeService businessTime;
+
+    public TeacherChangeRequestService(
+            TeacherChangeRequestRepository requestRepository,
+            TeacherChangeRequestHistoryRepository historyRepository,
+            ScheduleRuleSlotRepository ruleSlotRepository,
+            ScheduleOverrideRepository overrideRepository,
+            ClassroomRepository classroomRepository,
+            TeacherDepartmentAssignmentRepository assignmentRepository,
+            ScheduleQueryService scheduleQueryService,
+            ScheduleOverrideService scheduleOverrideService,
+            EffectiveTimeSlotService effectiveTimeSlotService,
+            BusinessTimeService businessTime
+    ) {
+        this.requestRepository = requestRepository;
+        this.historyRepository = historyRepository;
+        this.ruleSlotRepository = ruleSlotRepository;
+        this.overrideRepository = overrideRepository;
+        this.classroomRepository = classroomRepository;
+        this.assignmentRepository = assignmentRepository;
+        this.scheduleQueryService = scheduleQueryService;
+        this.scheduleOverrideService = scheduleOverrideService;
+        this.effectiveTimeSlotService = effectiveTimeSlotService;
+        this.businessTime = businessTime;
+    }
+
+    @Transactional(readOnly = true)
+    public List<TeacherChangeRequestDto> getAll(String status) {
+        AuthenticatedUser current = currentUser();
+        String normalizedStatus = cleanUpper(status);
+        if (normalizedStatus != null && !STATUSES.contains(normalizedStatus)) {
+            throw new IllegalArgumentException("Неизвестный статус заявки на изменение расписания");
+        }
+        return requestRepository.findAllWithDetails().stream()
+                .filter(request -> normalizedStatus == null || normalizedStatus.equals(request.getStatus()))
+                .filter(request -> canView(request, current))
+                .map(this::toDto)
+                .toList();
+    }
+
+    @Transactional(readOnly = true)
+    public TeacherChangeCandidatesDto getCandidates(
+            Long baseRuleSlotId,
+            LocalDate lessonDate,
+            LocalDate targetDate
+    ) {
+        AuthenticatedUser current = currentUser();
+        RenderedLessonDto lesson = sourceLesson(baseRuleSlotId, lessonDate);
+        ensureCanUseLesson(lesson, current);
+        var availability = scheduleOverrideService.getAvailability(baseRuleSlotId, lessonDate);
+        LocalDate checkedDate = targetDate == null ? lessonDate : targetDate;
+        if (!availability.availableDates().contains(checkedDate)) {
+            throw new IllegalArgumentException("Целевая дата недоступна для этого правила расписания");
+        }
+
+        List<TeacherChangeCandidatesDto.CandidateOption> timeSlots = effectiveTimeSlotService.findEffective(checkedDate)
+                .stream()
+                .sorted(Comparator.comparing(TimeSlot::getOrderNumber).thenComparing(TimeSlot::getStartTime))
+                .map(slot -> candidateOption(
+                        slot.getId(),
+                        slot.getOrderNumber() + " пара · " + shortTime(slot),
+                        buildOverride(
+                                baseRuleSlotId,
+                                lessonDate,
+                                checkedDate,
+                                "MOVE",
+                                slot.getId(),
+                                null,
+                                "Предварительная проверка заявки преподавателя"
+                        )
+                ))
+                .toList();
+        List<TeacherChangeCandidatesDto.CandidateOption> classrooms = classroomRepository.findByStatusNot("ARCHIVED")
+                .stream()
+                .filter(classroom -> Boolean.TRUE.equals(classroom.getIsAvailable()))
+                .sorted(Comparator.comparing(Classroom::getName))
+                .map(classroom -> candidateOption(
+                        classroom.getId(),
+                        classroom.getName(),
+                        buildOverride(
+                                baseRuleSlotId,
+                                lessonDate,
+                                lessonDate,
+                                "REPLACE",
+                                null,
+                                classroom.getId(),
+                                "Предварительная проверка заявки преподавателя"
+                        )
+                ))
+                .toList();
+        return new TeacherChangeCandidatesDto(
+                lesson,
+                availability.semesterId(),
+                availability.semesterStartDate(),
+                availability.semesterEndDate(),
+                availability.availableDates(),
+                checkedDate,
+                timeSlots,
+                classrooms
+        );
+    }
+
+    @Transactional
+    public TeacherChangeRequestDto create(TeacherChangeRequestPayload payload) {
+        AuthenticatedUser current = currentUser();
+        if (current.role() != Role.TEACHER) {
+            throw forbidden("Заявку на изменение занятия отправляет преподаватель");
+        }
+        if (payload == null || payload.baseRuleSlotId() == null || payload.lessonDate() == null) {
+            throw new IllegalArgumentException("Выберите занятие для заявки");
+        }
+        String type = cleanUpper(payload.requestType());
+        if (type == null || !TYPES.contains(type)) {
+            throw new IllegalArgumentException("Неизвестный тип изменения занятия");
+        }
+        String reason = clean(payload.reason());
+        if (reason == null) {
+            throw new IllegalArgumentException("Обоснование заявки обязательно");
+        }
+        if (reason.length() > 2000) {
+            throw new IllegalArgumentException("Обоснование не может превышать 2000 символов");
+        }
+        RenderedLessonDto lesson = sourceLesson(payload.baseRuleSlotId(), payload.lessonDate());
+        ensureCanUseLesson(lesson, current);
+        if (requestRepository.existsByBaseRuleSlotIdAndLessonDateAndStatus(
+                payload.baseRuleSlotId(), payload.lessonDate(), "PENDING")) {
+            throw new ScheduleConflictException("По выбранному занятию уже есть заявка на рассмотрении");
+        }
+
+        ScheduleRuleSlot baseSlot = ruleSlotRepository.findById(payload.baseRuleSlotId())
+                .orElseThrow(() -> new IllegalArgumentException("Базовый слот расписания не найден"));
+        ScheduleOverrideDto candidate = validatePayload(payload, type, lesson);
+        scheduleOverrideService.validateCandidate(candidate);
+
+        var now = businessTime.now();
+        TeacherChangeRequest request = new TeacherChangeRequest();
+        request.setTeacher(baseSlot.getTeacher());
+        request.setBaseRuleSlot(baseSlot);
+        request.setLessonDate(payload.lessonDate());
+        request.setRequestType(type);
+        request.setTargetLessonDate("MOVE".equals(type) ? candidate.targetLessonDate() : null);
+        request.setRequestedTimeSlot(candidate.newTimeSlotId() == null
+                ? null
+                : effectiveTimeSlotService.findEffective(
+                                candidate.targetLessonDate() == null ? payload.lessonDate() : candidate.targetLessonDate())
+                        .stream()
+                        .filter(slot -> Objects.equals(slot.getId(), candidate.newTimeSlotId()))
+                        .findFirst()
+                        .orElseThrow(() -> new IllegalArgumentException("Выбранный временной слот недоступен на целевую дату")));
+        request.setRequestedClassroom(candidate.newClassroomId() == null
+                ? null
+                : classroomRepository.findById(candidate.newClassroomId())
+                        .orElseThrow(() -> new IllegalArgumentException("Аудитория не найдена")));
+        request.setReason(reason);
+        request.setStatus("PENDING");
+        request.setCreatedAt(now);
+        request.setUpdatedAt(now);
+        TeacherChangeRequest saved = requestRepository.saveAndFlush(request);
+        addHistory(saved, "PENDING", reason, current.id(), now);
+        log.info("Преподаватель {} отправил заявку {} по занятию {} на {}",
+                current.id(), saved.getId(), payload.baseRuleSlotId(), payload.lessonDate());
+        return toDto(saved);
+    }
+
+    @Transactional
+    public TeacherChangeRequestDto review(Long id, TeacherChangeReviewRequest review) {
+        AuthenticatedUser current = currentUser();
+        if (current.role() != Role.ADMIN && current.role() != Role.EDUCATION_OFFICE) {
+            throw forbidden("Применять заявки на изменение расписания может только учебный отдел");
+        }
+        if (review == null || review.approved() == null) {
+            throw new IllegalArgumentException("Укажите решение по заявке");
+        }
+        TeacherChangeRequest request = requestRepository.findByIdForUpdate(id)
+                .orElseThrow(() -> new NoSuchElementException("Заявка на изменение расписания не найдена"));
+        if (!"PENDING".equals(request.getStatus())) {
+            throw new IllegalArgumentException("Рассмотреть можно только ожидающую заявку");
+        }
+        String comment = clean(review.comment());
+        if (!Boolean.TRUE.equals(review.approved()) && comment == null) {
+            throw new IllegalArgumentException("При отклонении укажите комментарий");
+        }
+        var now = businessTime.now();
+        if (Boolean.TRUE.equals(review.approved())) {
+            ScheduleOverrideDto applied = scheduleOverrideService.create(toOverride(request, comment));
+            ScheduleOverride override = overrideRepository.findById(applied.id())
+                    .orElseThrow(() -> new IllegalStateException("Применённое изменение расписания не найдено"));
+            request.setAppliedOverride(override);
+            request.setStatus("APPROVED");
+        } else {
+            request.setStatus("REJECTED");
+        }
+        request.setReviewedBy(current.id());
+        request.setReviewComment(comment);
+        request.setReviewedAt(now);
+        request.setUpdatedAt(now);
+        TeacherChangeRequest saved = requestRepository.saveAndFlush(request);
+        addHistory(saved, saved.getStatus(), comment, current.id(), now);
+        log.info("Заявка преподавателя {} переведена в статус {}", id, saved.getStatus());
+        return toDto(saved);
+    }
+
+    @Transactional
+    public TeacherChangeRequestDto cancel(Long id) {
+        AuthenticatedUser current = currentUser();
+        TeacherChangeRequest request = requestRepository.findByIdForUpdate(id)
+                .orElseThrow(() -> new NoSuchElementException("Заявка на изменение расписания не найдена"));
+        if (current.role() != Role.TEACHER || !Objects.equals(current.id(), request.getTeacher().getId())) {
+            throw forbidden("Отменить заявку может только отправивший её преподаватель");
+        }
+        if (!"PENDING".equals(request.getStatus())) {
+            throw new IllegalArgumentException("Отменить можно только ожидающую заявку");
+        }
+        var now = businessTime.now();
+        request.setStatus("CANCELLED");
+        request.setUpdatedAt(now);
+        TeacherChangeRequest saved = requestRepository.saveAndFlush(request);
+        addHistory(saved, "CANCELLED", "Заявка отозвана преподавателем", current.id(), now);
+        return toDto(saved);
+    }
+
+    private ScheduleOverrideDto validatePayload(
+            TeacherChangeRequestPayload payload,
+            String type,
+            RenderedLessonDto lesson
+    ) {
+        if ("MOVE".equals(type)) {
+            if (payload.requestedTimeSlotId() == null) {
+                throw new IllegalArgumentException("Для переноса выберите новую пару");
+            }
+            if (payload.requestedClassroomId() != null) {
+                throw new IllegalArgumentException("Смену аудитории оформите отдельным типом заявки");
+            }
+            LocalDate targetDate = payload.targetLessonDate() == null ? payload.lessonDate() : payload.targetLessonDate();
+            return buildOverride(payload.baseRuleSlotId(), payload.lessonDate(), targetDate, "MOVE",
+                    payload.requestedTimeSlotId(), null, payload.reason());
+        }
+        if ("CHANGE_CLASSROOM".equals(type)) {
+            if (payload.requestedClassroomId() == null) {
+                throw new IllegalArgumentException("Выберите новую аудиторию");
+            }
+            if (payload.targetLessonDate() != null || payload.requestedTimeSlotId() != null) {
+                throw new IllegalArgumentException("Для смены аудитории дата и время не изменяются");
+            }
+            if (Objects.equals(payload.requestedClassroomId(), lesson.classroomId())) {
+                throw new IllegalArgumentException("Новая аудитория должна отличаться от текущей");
+            }
+            return buildOverride(payload.baseRuleSlotId(), payload.lessonDate(), payload.lessonDate(), "REPLACE",
+                    null, payload.requestedClassroomId(), payload.reason());
+        }
+        if (payload.targetLessonDate() != null
+                || payload.requestedTimeSlotId() != null
+                || payload.requestedClassroomId() != null) {
+            throw new IllegalArgumentException("Для отмены занятия новые параметры не указываются");
+        }
+        return buildOverride(payload.baseRuleSlotId(), payload.lessonDate(), payload.lessonDate(), "CANCEL",
+                null, null, payload.reason());
+    }
+
+    private TeacherChangeCandidatesDto.CandidateOption candidateOption(
+            Long id,
+            String label,
+            ScheduleOverrideDto candidate
+    ) {
+        try {
+            scheduleOverrideService.validateCandidate(candidate);
+            return new TeacherChangeCandidatesDto.CandidateOption(id, label, true, null);
+        } catch (RuntimeException exception) {
+            return new TeacherChangeCandidatesDto.CandidateOption(id, label, false, exception.getMessage());
+        }
+    }
+
+    private ScheduleOverrideDto buildOverride(
+            Long baseRuleSlotId,
+            LocalDate lessonDate,
+            LocalDate targetDate,
+            String action,
+            Long timeSlotId,
+            Long classroomId,
+            String comment
+    ) {
+        LocalDate storedTargetDate = Objects.equals(lessonDate, targetDate) ? null : targetDate;
+        return new ScheduleOverrideDto(
+                null,
+                baseRuleSlotId,
+                lessonDate,
+                storedTargetDate,
+                action,
+                timeSlotId,
+                classroomId,
+                null,
+                null,
+                comment,
+                null,
+                null
+        );
+    }
+
+    private ScheduleOverrideDto toOverride(TeacherChangeRequest request, String reviewComment) {
+        String comment = "Одобрена заявка преподавателя №" + request.getId() + ": " + request.getReason();
+        if (reviewComment != null) comment += ". Решение: " + reviewComment;
+        String action = switch (request.getRequestType()) {
+            case "MOVE" -> "MOVE";
+            case "CHANGE_CLASSROOM" -> "REPLACE";
+            case "CANCEL" -> "CANCEL";
+            default -> throw new IllegalStateException("Неизвестный тип заявки");
+        };
+        return buildOverride(
+                request.getBaseRuleSlot().getId(),
+                request.getLessonDate(),
+                request.getTargetLessonDate() == null ? request.getLessonDate() : request.getTargetLessonDate(),
+                action,
+                request.getRequestedTimeSlot() == null ? null : request.getRequestedTimeSlot().getId(),
+                request.getRequestedClassroom() == null ? null : request.getRequestedClassroom().getId(),
+                comment
+        );
+    }
+
+    private RenderedLessonDto sourceLesson(Long baseRuleSlotId, LocalDate lessonDate) {
+        if (baseRuleSlotId == null || lessonDate == null) {
+            throw new IllegalArgumentException("Базовый слот и дата занятия обязательны");
+        }
+        if (overrideRepository.findByBaseRuleSlotIdAndLessonDate(baseRuleSlotId, lessonDate).isPresent()) {
+            throw new ScheduleConflictException("Для занятия уже существует точечное изменение расписания");
+        }
+        return scheduleQueryService.buildBaseDayForAllGroups(lessonDate).stream()
+                .filter(lesson -> Objects.equals(lesson.scheduleRuleSlotId(), baseRuleSlotId))
+                .filter(lesson -> Objects.equals(lesson.date(), lessonDate))
+                .findFirst()
+                .orElseThrow(() -> new IllegalArgumentException("Выбранное занятие не найдено в базовом расписании"));
+    }
+
+    private void ensureCanUseLesson(RenderedLessonDto lesson, AuthenticatedUser current) {
+        if (current.role() == Role.ADMIN || current.role() == Role.EDUCATION_OFFICE) return;
+        if (current.role() == Role.TEACHER && Objects.equals(current.id(), lesson.teacherId())) return;
+        if (current.role() == Role.DEPARTMENT
+                && current.departmentId() != null
+                && assignmentRepository.existsActiveAssignment(
+                        lesson.teacherId(), current.departmentId(), lesson.date())) return;
+        throw forbidden("Выбранное занятие находится вне доступной области");
+    }
+
+    private boolean canView(TeacherChangeRequest request, AuthenticatedUser current) {
+        if (current.role() == Role.ADMIN || current.role() == Role.EDUCATION_OFFICE) return true;
+        if (current.role() == Role.TEACHER) {
+            return Objects.equals(current.id(), request.getTeacher().getId());
+        }
+        return current.role() == Role.DEPARTMENT
+                && current.departmentId() != null
+                && assignmentRepository.existsActiveAssignment(
+                        request.getTeacher().getId(), current.departmentId(), request.getLessonDate());
+    }
+
+    private void addHistory(
+            TeacherChangeRequest request,
+            String status,
+            String comment,
+            Long actorId,
+            java.time.Instant now
+    ) {
+        TeacherChangeRequestHistory history = new TeacherChangeRequestHistory();
+        history.setRequest(request);
+        history.setStatus(status);
+        history.setComment(comment);
+        history.setActorId(actorId);
+        history.setCreatedAt(now);
+        historyRepository.save(history);
+    }
+
+    private TeacherChangeRequestDto toDto(TeacherChangeRequest request) {
+        ScheduleRuleSlot source = request.getBaseRuleSlot();
+        TimeSlot sourceSlot = source.getTimeSlot();
+        TimeSlot targetSlot = request.getRequestedTimeSlot();
+        Classroom sourceClassroom = source.getClassroom();
+        Classroom targetClassroom = request.getRequestedClassroom();
+        List<TeacherChangeRequestDto.HistoryItem> history = historyRepository
+                .findByRequestIdOrderByCreatedAtAscIdAsc(request.getId()).stream()
+                .map(item -> new TeacherChangeRequestDto.HistoryItem(
+                        item.getId(), item.getStatus(), item.getComment(), item.getActorId(), item.getCreatedAt()))
+                .toList();
+        return new TeacherChangeRequestDto(
+                request.getId(),
+                request.getTeacher().getId(),
+                ScheduleGeneratorService.displayUserName(request.getTeacher()),
+                request.getTeacher().getDepartmentId(),
+                source.getId(),
+                request.getLessonDate(),
+                source.getScheduleRule().getSubject().getName(),
+                source.getLessonType().getLessonType(),
+                source.getScheduleRule().getGroups().stream().map(group -> group.getName()).sorted().toList(),
+                sourceSlot.getId(),
+                sourceSlot.getOrderNumber(),
+                sourceSlot.getStartTime(),
+                sourceSlot.getEndTime(),
+                sourceClassroom.getId(),
+                sourceClassroom.getName(),
+                request.getRequestType(),
+                request.getTargetLessonDate(),
+                targetSlot == null ? null : targetSlot.getId(),
+                targetSlot == null ? null : targetSlot.getOrderNumber(),
+                targetSlot == null ? null : targetSlot.getStartTime(),
+                targetSlot == null ? null : targetSlot.getEndTime(),
+                targetClassroom == null ? null : targetClassroom.getId(),
+                targetClassroom == null ? null : targetClassroom.getName(),
+                request.getReason(),
+                request.getStatus(),
+                request.getReviewedBy(),
+                request.getReviewComment(),
+                request.getReviewedAt(),
+                request.getAppliedOverride() == null ? null : request.getAppliedOverride().getId(),
+                request.getCreatedAt(),
+                request.getUpdatedAt(),
+                history
+        );
+    }
+
+    private String shortTime(TimeSlot slot) {
+        return slot.getStartTime().toString() + "–" + slot.getEndTime();
+    }
+
+    private AuthenticatedUser currentUser() {
+        AuthenticatedUser current = AuthContext.getCurrentUser();
+        if (current == null) throw new ResponseStatusException(HttpStatus.UNAUTHORIZED, "Требуется авторизация");
+        return current;
+    }
+
+    private ResponseStatusException forbidden(String message) {
+        return new ResponseStatusException(HttpStatus.FORBIDDEN, message);
+    }
+
+    private String clean(String value) {
+        return value == null || value.isBlank() ? null : value.trim();
+    }
+
+    private String cleanUpper(String value) {
+        String cleaned = clean(value);
+        return cleaned == null ? null : cleaned.toUpperCase(Locale.ROOT);
+    }
+}
--- a/backend/src/main/java/com/magistr/app/service/TeacherDepartmentService.java
+++ b/backend/src/main/java/com/magistr/app/service/TeacherDepartmentService.java
@@ -136,6 +136,23 @@ public class TeacherDepartmentService {
                .findFirst();
    }

+    public boolean hasDepartmentAssignmentAtDate(
+            Collection<TeacherDepartmentAssignment> assignments,
+            Long departmentId,
+            LocalDate date
+    ) {
+        if (assignments == null || departmentId == null || date == null) {
+            return false;
+        }
+        return assignments.stream()
+                .filter(Objects::nonNull)
+                .filter(assignment -> isActiveAt(assignment, date))
+                .map(TeacherDepartmentAssignment::getDepartment)
+                .filter(Objects::nonNull)
+                .map(Department::getId)
+                .anyMatch(departmentId::equals);
+    }
+
    @Transactional
    public TeacherDepartmentAssignment transferTeacher(Long teacherId,
                                                        DepartmentTransferRequest request,
--- a/backend/src/main/java/com/magistr/app/service/TeacherPreferenceService.java
+++ b/backend/src/main/java/com/magistr/app/service/TeacherPreferenceService.java
@@ -0,0 +1,368 @@
+package com.magistr.app.service;
+
+import com.magistr.app.config.auth.AuthContext;
+import com.magistr.app.config.auth.AuthenticatedUser;
+import com.magistr.app.dto.SemesterDto;
+import com.magistr.app.dto.TeacherPreferenceDto;
+import com.magistr.app.dto.TeacherPreferenceMetaDto;
+import com.magistr.app.dto.TeacherPreferenceRequest;
+import com.magistr.app.dto.TeacherPreferenceReviewRequest;
+import com.magistr.app.dto.TimeSlotDto;
+import com.magistr.app.model.Role;
+import com.magistr.app.model.Semester;
+import com.magistr.app.model.TeacherPreference;
+import com.magistr.app.model.TimeSlot;
+import com.magistr.app.model.User;
+import com.magistr.app.repository.SemesterRepository;
+import com.magistr.app.repository.TeacherDepartmentAssignmentRepository;
+import com.magistr.app.repository.TeacherPreferenceRepository;
+import com.magistr.app.repository.TimeSlotRepository;
+import com.magistr.app.repository.UserRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.time.DayOfWeek;
+import java.time.LocalDate;
+import java.time.format.TextStyle;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Locale;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.Set;
+
+@Service
+public class TeacherPreferenceService {
+
+    private static final Logger log = LoggerFactory.getLogger(TeacherPreferenceService.class);
+    private static final Set<String> TYPES = Set.of(
+            "HARD_UNAVAILABLE", "SOFT_PREFERRED", "SOFT_UNWANTED", "CONSECUTIVE", "NO_GAPS"
+    );
+    private static final Set<String> STATUSES = Set.of("PENDING", "APPROVED", "REJECTED", "CANCELLED");
+    private static final Set<String> ACTIVE_STATUSES = Set.of("PENDING", "APPROVED");
+
+    private final TeacherPreferenceRepository preferenceRepository;
+    private final UserRepository userRepository;
+    private final SemesterRepository semesterRepository;
+    private final TimeSlotRepository timeSlotRepository;
+    private final TeacherDepartmentAssignmentRepository assignmentRepository;
+    private final BusinessTimeService businessTime;
+
+    public TeacherPreferenceService(
+            TeacherPreferenceRepository preferenceRepository,
+            UserRepository userRepository,
+            SemesterRepository semesterRepository,
+            TimeSlotRepository timeSlotRepository,
+            TeacherDepartmentAssignmentRepository assignmentRepository,
+            BusinessTimeService businessTime
+    ) {
+        this.preferenceRepository = preferenceRepository;
+        this.userRepository = userRepository;
+        this.semesterRepository = semesterRepository;
+        this.timeSlotRepository = timeSlotRepository;
+        this.assignmentRepository = assignmentRepository;
+        this.businessTime = businessTime;
+    }
+
+    @Transactional(readOnly = true)
+    public TeacherPreferenceMetaDto getMeta() {
+        List<SemesterDto> semesters = semesterRepository.findAll().stream()
+                .sorted(Comparator.comparing(Semester::getStartDate).reversed())
+                .map(semester -> new SemesterDto(
+                        semester.getId(),
+                        semester.getAcademicYear().getId(),
+                        semester.getAcademicYear().getTitle(),
+                        semester.getSemesterType(),
+                        semester.getStartDate(),
+                        semester.getEndDate()
+                ))
+                .toList();
+        List<TimeSlotDto> timeSlots = timeSlotRepository.findAllForSchedule().stream()
+                .filter(slot -> slot.getTimeSlotScope() != null)
+                .filter(slot -> "DEFAULT".equals(slot.getTimeSlotScope().getApplyMode()))
+                .map(this::toTimeSlotDto)
+                .toList();
+        return new TeacherPreferenceMetaDto(semesters, timeSlots);
+    }
+
+    @Transactional(readOnly = true)
+    public List<TeacherPreferenceDto> getAll(Long semesterId, String status) {
+        AuthenticatedUser current = currentUser();
+        String normalizedStatus = cleanUpper(status);
+        if (normalizedStatus != null && !STATUSES.contains(normalizedStatus)) {
+            throw new IllegalArgumentException("Неизвестный статус пожелания преподавателя");
+        }
+        return preferenceRepository.findAllWithDetails().stream()
+                .filter(thisPreference -> semesterId == null
+                        || Objects.equals(thisPreference.getSemester().getId(), semesterId))
+                .filter(thisPreference -> normalizedStatus == null
+                        || normalizedStatus.equals(thisPreference.getStatus()))
+                .filter(thisPreference -> canView(thisPreference, current))
+                .map(this::toDto)
+                .toList();
+    }
+
+    @Transactional
+    public TeacherPreferenceDto create(TeacherPreferenceRequest request) {
+        AuthenticatedUser current = currentUser();
+        if (request == null) {
+            throw new IllegalArgumentException("Передайте данные пожелания преподавателя");
+        }
+        String type = cleanUpper(request.preferenceType());
+        if (type == null || !TYPES.contains(type)) {
+            throw new IllegalArgumentException("Неизвестный тип пожелания преподавателя");
+        }
+        if (request.semesterId() == null) {
+            throw new IllegalArgumentException("Выберите семестр");
+        }
+        Semester semester = semesterRepository.findById(request.semesterId())
+                .orElseThrow(() -> new IllegalArgumentException("Семестр не найден"));
+        Long teacherId = current.role() == Role.TEACHER ? current.id() : request.teacherId();
+        if (teacherId == null) {
+            throw new IllegalArgumentException("Выберите преподавателя");
+        }
+        if (current.role() == Role.TEACHER
+                && request.teacherId() != null
+                && !Objects.equals(request.teacherId(), current.id())) {
+            throw forbidden("Преподаватель может создавать пожелания только для себя");
+        }
+        User teacher = userRepository.findById(teacherId)
+                .filter(user -> user.getRole() == Role.TEACHER)
+                .filter(User::isActiveRecord)
+                .orElseThrow(() -> new IllegalArgumentException("Преподаватель не найден"));
+        ensureManageScope(teacher, semester, current);
+
+        PreferencePayload payload = validatePayload(type, semester, request);
+        String comment = clean(request.comment());
+        if (comment != null && comment.length() > 2000) {
+            throw new IllegalArgumentException("Комментарий не может превышать 2000 символов");
+        }
+        if (preferenceRepository.existsDuplicate(
+                teacherId,
+                semester.getId(),
+                type,
+                payload.dayOfWeek(),
+                payload.timeSlot() == null ? null : payload.timeSlot().getId(),
+                payload.preferenceDate(),
+                ACTIVE_STATUSES
+        )) {
+            throw new ScheduleConflictException("Такое пожелание уже ожидает решения или согласовано");
+        }
+
+        var now = businessTime.now();
+        TeacherPreference preference = new TeacherPreference();
+        preference.setTeacher(teacher);
+        preference.setSemester(semester);
+        preference.setPreferenceType(type);
+        preference.setDayOfWeek(payload.dayOfWeek());
+        preference.setTimeSlot(payload.timeSlot());
+        preference.setPreferenceDate(payload.preferenceDate());
+        preference.setComment(comment);
+        preference.setRequestedBy(current.id());
+        preference.setCreatedAt(now);
+        preference.setUpdatedAt(now);
+        if (current.role() == Role.TEACHER) {
+            preference.setStatus("PENDING");
+        } else {
+            preference.setStatus("APPROVED");
+            preference.setReviewedBy(current.id());
+            preference.setReviewedAt(now);
+            preference.setReviewComment("Добавлено ответственным сотрудником");
+        }
+        TeacherPreference saved = preferenceRepository.saveAndFlush(preference);
+        log.info("Создано пожелание преподавателя {} на семестр {}, тип {}", teacherId, semester.getId(), type);
+        return toDto(saved);
+    }
+
+    @Transactional
+    public TeacherPreferenceDto review(Long id, TeacherPreferenceReviewRequest request) {
+        AuthenticatedUser current = currentUser();
+        if (current.role() == Role.TEACHER) {
+            throw forbidden("Преподаватель не может согласовывать пожелания");
+        }
+        if (request == null || request.approved() == null) {
+            throw new IllegalArgumentException("Укажите решение по пожеланию преподавателя");
+        }
+        TeacherPreference preference = getForUpdate(id);
+        ensureManageScope(preference.getTeacher(), preference.getSemester(), current);
+        if (!"PENDING".equals(preference.getStatus())) {
+            throw new IllegalArgumentException("Рассмотреть можно только ожидающее пожелание");
+        }
+        String comment = clean(request.comment());
+        if (!Boolean.TRUE.equals(request.approved()) && comment == null) {
+            throw new IllegalArgumentException("При отклонении укажите комментарий");
+        }
+        var now = businessTime.now();
+        preference.setStatus(Boolean.TRUE.equals(request.approved()) ? "APPROVED" : "REJECTED");
+        preference.setReviewedBy(current.id());
+        preference.setReviewComment(comment);
+        preference.setReviewedAt(now);
+        preference.setUpdatedAt(now);
+        TeacherPreference saved = preferenceRepository.saveAndFlush(preference);
+        log.info("Пожелание преподавателя {} переведено в статус {}", id, saved.getStatus());
+        return toDto(saved);
+    }
+
+    @Transactional
+    public TeacherPreferenceDto cancel(Long id) {
+        AuthenticatedUser current = currentUser();
+        TeacherPreference preference = getForUpdate(id);
+        if (current.role() == Role.TEACHER) {
+            if (!Objects.equals(current.id(), preference.getTeacher().getId())) {
+                throw forbidden("Нельзя отменить пожелание другого преподавателя");
+            }
+            if (!"PENDING".equals(preference.getStatus())) {
+                throw new IllegalArgumentException("Преподаватель может отменить только ожидающее пожелание");
+            }
+        } else {
+            ensureManageScope(preference.getTeacher(), preference.getSemester(), current);
+            if (!Set.of("PENDING", "APPROVED").contains(preference.getStatus())) {
+                throw new IllegalArgumentException("Это пожелание уже нельзя отменить");
+            }
+        }
+        preference.setStatus("CANCELLED");
+        preference.setUpdatedAt(businessTime.now());
+        return toDto(preferenceRepository.saveAndFlush(preference));
+    }
+
+    private PreferencePayload validatePayload(String type, Semester semester, TeacherPreferenceRequest request) {
+        boolean compact = Set.of("CONSECUTIVE", "NO_GAPS").contains(type);
+        if (compact) {
+            if (request.dayOfWeek() != null || request.timeSlotId() != null || request.preferenceDate() != null) {
+                throw new IllegalArgumentException("Для пожелания к компактности день, дата и пара не указываются");
+            }
+            return new PreferencePayload(null, null, null);
+        }
+        if (request.preferenceDate() != null) {
+            if (!"HARD_UNAVAILABLE".equals(type)) {
+                throw new IllegalArgumentException("Полную недоступность по дате можно отметить только как строгую");
+            }
+            if (request.dayOfWeek() != null || request.timeSlotId() != null) {
+                throw new IllegalArgumentException("Для полной недоступности по дате день недели и пара не указываются");
+            }
+            if (request.preferenceDate().isBefore(semester.getStartDate())
+                    || request.preferenceDate().isAfter(semester.getEndDate())) {
+                throw new IllegalArgumentException("Дата недоступности должна находиться внутри семестра");
+            }
+            return new PreferencePayload(null, null, request.preferenceDate());
+        }
+        if (request.dayOfWeek() == null || request.dayOfWeek() < 1 || request.dayOfWeek() > 7) {
+            throw new IllegalArgumentException("Выберите день недели");
+        }
+        if (request.timeSlotId() == null) {
+            throw new IllegalArgumentException("Выберите временной слот");
+        }
+        TimeSlot slot = timeSlotRepository.findById(request.timeSlotId())
+                .orElseThrow(() -> new IllegalArgumentException("Временной слот не найден"));
+        if (slot.getTimeSlotScope() == null || !"DEFAULT".equals(slot.getTimeSlotScope().getApplyMode())) {
+            throw new IllegalArgumentException("Для пожеланий используйте базовую сетку времени");
+        }
+        return new PreferencePayload(request.dayOfWeek(), slot, null);
+    }
+
+    private TeacherPreference getForUpdate(Long id) {
+        return preferenceRepository.findByIdForUpdate(id)
+                .orElseThrow(() -> new NoSuchElementException("Пожелание преподавателя не найдено"));
+    }
+
+    private boolean canView(TeacherPreference preference, AuthenticatedUser current) {
+        if (current.role() == Role.ADMIN || current.role() == Role.EDUCATION_OFFICE) return true;
+        if (current.role() == Role.TEACHER) {
+            return Objects.equals(current.id(), preference.getTeacher().getId());
+        }
+        return current.role() == Role.DEPARTMENT
+                && belongsToDepartment(preference.getTeacher(), preference.getSemester(), current.departmentId());
+    }
+
+    private void ensureManageScope(User teacher, Semester semester, AuthenticatedUser current) {
+        if (current.role() == Role.ADMIN || current.role() == Role.EDUCATION_OFFICE) return;
+        if (current.role() == Role.TEACHER && Objects.equals(current.id(), teacher.getId())) return;
+        if (current.role() == Role.DEPARTMENT
+                && belongsToDepartment(teacher, semester, current.departmentId())) return;
+        throw forbidden("Пожелание преподавателя находится вне доступной кафедры");
+    }
+
+    private boolean belongsToDepartment(User teacher, Semester semester, Long departmentId) {
+        if (departmentId == null) return false;
+        return assignmentRepository.findForTeachersBetween(
+                        Set.of(teacher.getId()),
+                        semester.getStartDate(),
+                        semester.getEndDate()
+                ).stream()
+                .anyMatch(assignment -> assignment.getDepartment() != null
+                        && Objects.equals(assignment.getDepartment().getId(), departmentId));
+    }
+
+    private TeacherPreferenceDto toDto(TeacherPreference preference) {
+        User teacher = preference.getTeacher();
+        Semester semester = preference.getSemester();
+        TimeSlot slot = preference.getTimeSlot();
+        return new TeacherPreferenceDto(
+                preference.getId(),
+                teacher.getId(),
+                ScheduleGeneratorService.displayUserName(teacher),
+                teacher.getDepartmentId(),
+                semester.getId(),
+                semester.getAcademicYear().getTitle(),
+                semester.getSemesterType().name(),
+                semester.getStartDate(),
+                semester.getEndDate(),
+                preference.getPreferenceType(),
+                preference.getDayOfWeek(),
+                dayName(preference.getDayOfWeek()),
+                slot == null ? null : slot.getId(),
+                slot == null ? null : slot.getOrderNumber(),
+                slot == null ? null : slot.getStartTime(),
+                slot == null ? null : slot.getEndTime(),
+                preference.getPreferenceDate(),
+                preference.getComment(),
+                preference.getStatus(),
+                preference.getRequestedBy(),
+                preference.getReviewedBy(),
+                preference.getReviewComment(),
+                preference.getReviewedAt(),
+                preference.getCreatedAt(),
+                preference.getUpdatedAt()
+        );
+    }
+
+    private TimeSlotDto toTimeSlotDto(TimeSlot slot) {
+        var scope = slot.getTimeSlotScope();
+        return new TimeSlotDto(
+                slot.getId(), slot.getOrderNumber(), scope.getId(), scope.getName(), scope.getApplyMode(),
+                scope.getDayOfWeek(), slot.getStartTime(), slot.getEndTime(), slot.getDurationMinutes()
+        );
+    }
+
+    private String dayName(Integer dayOfWeek) {
+        if (dayOfWeek == null || dayOfWeek < 1 || dayOfWeek > 7) return null;
+        String value = DayOfWeek.of(dayOfWeek).getDisplayName(TextStyle.FULL, Locale.forLanguageTag("ru"));
+        return value.substring(0, 1).toUpperCase(Locale.forLanguageTag("ru")) + value.substring(1);
+    }
+
+    private AuthenticatedUser currentUser() {
+        AuthenticatedUser current = AuthContext.getCurrentUser();
+        if (current == null) throw new ResponseStatusException(HttpStatus.UNAUTHORIZED, "Требуется авторизация");
+        return current;
+    }
+
+    private ResponseStatusException forbidden(String message) {
+        return new ResponseStatusException(HttpStatus.FORBIDDEN, message);
+    }
+
+    private String clean(String value) {
+        return value == null || value.isBlank() ? null : value.trim();
+    }
+
+    private String cleanUpper(String value) {
+        String cleaned = clean(value);
+        return cleaned == null ? null : cleaned.toUpperCase(Locale.ROOT);
+    }
+
+    private record PreferencePayload(Integer dayOfWeek, TimeSlot timeSlot, LocalDate preferenceDate) {
+    }
+}
--- a/backend/src/main/resources/db/migration/V1__init.sql
+++ b/backend/src/main/resources/db/migration/V1__init.sql
@@ -2,6 +2,7 @@
 -- Инициализация расширений
 -- ==========================================
 CREATE EXTENSION IF NOT EXISTS pgcrypto;
+CREATE EXTENSION IF NOT EXISTS btree_gist;

 -- ===============================
 -- Справочники высшего уровня
@@ -714,22 +715,25 @@ JOIN specialty_profiles profile ON profile.specialty_id = specialty.id AND profi
 WHERE ay.title = '2025-2026'
 ON CONFLICT (academic_year_id, specialty_profile_id, study_form_id, title) DO NOTHING;

-CREATE TABLE IF NOT EXISTS academic_calendar_days (
+CREATE TABLE IF NOT EXISTS academic_calendar_periods (
    id BIGSERIAL PRIMARY KEY,
    calendar_id BIGINT NOT NULL REFERENCES academic_calendars(id) ON DELETE CASCADE,
    course_number INT NOT NULL,
-    date DATE NOT NULL,
-    week_number INT NOT NULL,
-    day_of_week INT NOT NULL,
+    start_date DATE NOT NULL,
+    end_date DATE NOT NULL,
    activity_type_id BIGINT NOT NULL REFERENCES academic_calendar_activity_types(id),
-    CONSTRAINT chk_calendar_days_course_positive CHECK (course_number > 0),
-    CONSTRAINT chk_calendar_days_week_positive CHECK (week_number > 0),
-    CONSTRAINT chk_calendar_days_day CHECK (day_of_week BETWEEN 1 AND 7),
-    CONSTRAINT uq_calendar_days UNIQUE (calendar_id, course_number, date)
+    CONSTRAINT chk_calendar_periods_course_positive CHECK (course_number > 0),
+    CONSTRAINT chk_calendar_periods_dates CHECK (end_date >= start_date),
+    CONSTRAINT ex_calendar_periods_no_overlap
+        EXCLUDE USING gist (
+            calendar_id WITH =,
+            course_number WITH =,
+            (daterange(start_date, end_date, '[]')) WITH &&
+        )
 );

-CREATE INDEX IF NOT EXISTS idx_calendar_days_lookup
-    ON academic_calendar_days(calendar_id, course_number, date);
+CREATE INDEX IF NOT EXISTS idx_calendar_periods_schedule
+    ON academic_calendar_periods(calendar_id, course_number, start_date, end_date);

 CREATE OR REPLACE FUNCTION calculate_academic_calendar_week_number(
    academic_year_start DATE,
@@ -750,20 +754,23 @@ AS $$
    ) + 1
 $$;

-INSERT INTO academic_calendar_days (calendar_id, course_number, date, week_number, day_of_week, activity_type_id)
+INSERT INTO academic_calendar_periods (
+    calendar_id,
+    course_number,
+    start_date,
+    end_date,
+    activity_type_id
+)
 SELECT
    calendar.id,
    course.course_number,
-    days.date::DATE,
-    calculate_academic_calendar_week_number(ay.start_date, days.date::DATE),
-    EXTRACT(ISODOW FROM days.date::DATE)::INT,
+    ay.start_date,
+    ay.end_date,
    activity.id
 FROM academic_calendars calendar
 JOIN academic_years ay ON ay.id = calendar.academic_year_id
 JOIN academic_calendar_activity_types activity ON activity.code = 'Т'
-CROSS JOIN GENERATE_SERIES(1, calendar.course_count) AS course(course_number)
-CROSS JOIN GENERATE_SERIES(ay.start_date, ay.end_date, INTERVAL '1 day') AS days(date)
-ON CONFLICT (calendar_id, course_number, date) DO NOTHING;
+CROSS JOIN GENERATE_SERIES(1, calendar.course_count) AS course(course_number);

 CREATE TABLE IF NOT EXISTS academic_calendar_subjects (
    id BIGSERIAL PRIMARY KEY,
@@ -1134,7 +1141,7 @@ COMMENT ON TABLE academic_years IS 'Учебные годы';
 COMMENT ON TABLE semesters IS 'Семестры учебного года';
 COMMENT ON TABLE academic_calendar_activity_types IS 'Коды активностей календарного учебного графика';
 COMMENT ON TABLE academic_calendars IS 'Календарные учебные графики по профилю, форме обучения и учебному году';
-COMMENT ON TABLE academic_calendar_days IS 'Дневные ячейки календарного учебного графика';
+COMMENT ON TABLE academic_calendar_periods IS 'Непересекающиеся периоды активности календарного учебного графика';
 COMMENT ON TABLE academic_calendar_subjects IS 'Привязка дисциплин к календарному учебному графику по номерам учебных семестров';
 COMMENT ON TABLE student_group_calendar_assignments IS 'Назначения календарных графиков учебным группам по учебному году';
 COMMENT ON TABLE schedule_rules IS 'Правила динамической генерации расписания';
@@ -1275,12 +1282,11 @@ COMMENT ON COLUMN academic_calendars.specialty_profile_id IS 'ID профиля
 COMMENT ON COLUMN academic_calendars.study_form_id IS 'ID формы обучения из education_forms';
 COMMENT ON COLUMN academic_calendars.course_count IS 'Количество курсов в графике';

-COMMENT ON COLUMN academic_calendar_days.calendar_id IS 'ID календарного учебного графика';
-COMMENT ON COLUMN academic_calendar_days.course_number IS 'Номер курса';
-COMMENT ON COLUMN academic_calendar_days.date IS 'Дата';
-COMMENT ON COLUMN academic_calendar_days.week_number IS 'Номер недели в учебном году';
-COMMENT ON COLUMN academic_calendar_days.day_of_week IS 'День недели ISO';
-COMMENT ON COLUMN academic_calendar_days.activity_type_id IS 'ID кода активности';
+COMMENT ON COLUMN academic_calendar_periods.calendar_id IS 'ID календарного учебного графика';
+COMMENT ON COLUMN academic_calendar_periods.course_number IS 'Номер курса';
+COMMENT ON COLUMN academic_calendar_periods.start_date IS 'Первая дата периода включительно';
+COMMENT ON COLUMN academic_calendar_periods.end_date IS 'Последняя дата периода включительно';
+COMMENT ON COLUMN academic_calendar_periods.activity_type_id IS 'ID кода активности';
 COMMENT ON FUNCTION calculate_academic_calendar_week_number(DATE, DATE)
    IS 'Номер недели календарного учебного графика по периодам понедельник–воскресенье';

@@ -1579,8 +1585,6 @@ BEGIN
    END IF;
 END $$;

-CREATE EXTENSION IF NOT EXISTS btree_gist;
-
 ALTER TABLE time_slots
    ADD CONSTRAINT chk_time_slots_duration_matches_range
        CHECK (
@@ -1818,7 +1822,7 @@ CREATE TRIGGER trg_academic_years_include_semesters
 DO $$
 DECLARE
    assignment_violations BIGINT;
-    calendar_day_violations BIGINT;
+    calendar_period_violations BIGINT;
    calendar_subject_violations BIGINT;
 BEGIN
    SELECT count(*)
@@ -1840,13 +1844,13 @@ BEGIN
          END NOT BETWEEN 1 AND calendar.course_count;

    SELECT count(*)
-    INTO calendar_day_violations
-    FROM academic_calendar_days calendar_day
-    JOIN academic_calendars calendar ON calendar.id = calendar_day.calendar_id
+    INTO calendar_period_violations
+    FROM academic_calendar_periods calendar_period
+    JOIN academic_calendars calendar ON calendar.id = calendar_period.calendar_id
    JOIN academic_years academic_year ON academic_year.id = calendar.academic_year_id
-    WHERE calendar_day.course_number > calendar.course_count
-       OR calendar_day.date < academic_year.start_date
-       OR calendar_day.date > academic_year.end_date;
+    WHERE calendar_period.course_number > calendar.course_count
+       OR calendar_period.start_date < academic_year.start_date
+       OR calendar_period.end_date > academic_year.end_date;

    SELECT count(*)
    INTO calendar_subject_violations
@@ -1855,14 +1859,14 @@ BEGIN
    WHERE calendar_subject.semester_number > calendar.course_count * 2;

    IF assignment_violations > 0
-        OR calendar_day_violations > 0
+        OR calendar_period_violations > 0
        OR calendar_subject_violations > 0 THEN
        RAISE EXCEPTION USING
            ERRCODE = '23514',
            MESSAGE = format(
-                'Невозможно создать baseline: несовместимые назначения графиков=%s, строки сетки вне измерений=%s, дисциплины вне измерений=%s. Исправьте seed-данные V1 и повторите создание схемы.',
+                'Невозможно создать baseline: несовместимые назначения графиков=%s, периоды активности вне измерений=%s, дисциплины вне измерений=%s. Исправьте seed-данные V1 и повторите создание схемы.',
                assignment_violations,
-                calendar_day_violations,
+                calendar_period_violations,
                calendar_subject_violations
            );
    END IF;
@@ -1990,12 +1994,12 @@ BEGIN

    IF EXISTS (
        SELECT 1
-        FROM academic_calendar_days calendar_day
-        WHERE calendar_day.calendar_id = OLD.id
+        FROM academic_calendar_periods calendar_period
+        WHERE calendar_period.calendar_id = OLD.id
          AND (
-              calendar_day.course_number > NEW.course_count
-              OR calendar_day.date < academic_year_start
-              OR calendar_day.date > academic_year_end
+              calendar_period.course_number > NEW.course_count
+              OR calendar_period.start_date < academic_year_start
+              OR calendar_period.end_date > academic_year_end
          )
    ) THEN
        RAISE EXCEPTION USING
@@ -2059,7 +2063,7 @@ CREATE TRIGGER trg_student_groups_protect_calendar_assignments
    FOR EACH ROW
    EXECUTE FUNCTION prevent_incompatible_student_group_change();

-CREATE OR REPLACE FUNCTION enforce_calendar_day_dimensions()
+CREATE OR REPLACE FUNCTION enforce_calendar_period_dimensions()
 RETURNS TRIGGER
 LANGUAGE plpgsql
 AS $$
@@ -2078,22 +2082,22 @@ BEGIN
    IF calendar_course_count IS NOT NULL
        AND (
            NEW.course_number > calendar_course_count
-            OR NEW.date < academic_year_start
-            OR NEW.date > academic_year_end
+            OR NEW.start_date < academic_year_start
+            OR NEW.end_date > academic_year_end
        ) THEN
        RAISE EXCEPTION USING
            ERRCODE = '23514',
-            MESSAGE = 'Строка сетки выходит за измерения календарного графика';
+            MESSAGE = 'Период активности выходит за измерения календарного графика';
    END IF;

    RETURN NEW;
 END $$;

-CREATE TRIGGER trg_calendar_days_dimensions
-    BEFORE INSERT OR UPDATE OF calendar_id, course_number, date
-    ON academic_calendar_days
+CREATE TRIGGER trg_calendar_periods_dimensions
+    BEFORE INSERT OR UPDATE OF calendar_id, course_number, start_date, end_date
+    ON academic_calendar_periods
    FOR EACH ROW
-    EXECUTE FUNCTION enforce_calendar_day_dimensions();
+    EXECUTE FUNCTION enforce_calendar_period_dimensions();

 CREATE OR REPLACE FUNCTION enforce_calendar_subject_dimensions()
 RETURNS TRIGGER
@@ -2132,11 +2136,11 @@ BEGIN
    IF EXISTS (
        SELECT 1
        FROM academic_calendars calendar
-        JOIN academic_calendar_days calendar_day ON calendar_day.calendar_id = calendar.id
+        JOIN academic_calendar_periods calendar_period ON calendar_period.calendar_id = calendar.id
        WHERE calendar.academic_year_id = OLD.id
          AND (
-              calendar_day.date < NEW.start_date
-              OR calendar_day.date > NEW.end_date
+              calendar_period.start_date < NEW.start_date
+              OR calendar_period.end_date > NEW.end_date
          )
    ) OR EXISTS (
        SELECT 1
@@ -2178,3 +2182,323 @@ ALTER TABLE teacher_department_assignments
 COMMENT ON CONSTRAINT ex_teacher_primary_department_no_overlap
    ON teacher_department_assignments
    IS 'У преподавателя не могут пересекаться периоды двух основных кафедр';
+
+-- ==========================================
+-- Отсутствия преподавателей и мастер замены
+-- ==========================================
+CREATE TABLE teacher_absences (
+    id BIGSERIAL PRIMARY KEY,
+    teacher_id BIGINT NOT NULL REFERENCES users(id),
+    start_date DATE NOT NULL,
+    end_date DATE NOT NULL,
+    reason TEXT NOT NULL,
+    status VARCHAR(20) NOT NULL,
+    requested_by BIGINT REFERENCES users(id),
+    reviewed_by BIGINT REFERENCES users(id),
+    review_comment TEXT,
+    reviewed_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT chk_teacher_absences_period CHECK (end_date >= start_date),
+    CONSTRAINT chk_teacher_absences_reason CHECK (length(trim(reason)) BETWEEN 1 AND 2000),
+    CONSTRAINT chk_teacher_absences_status CHECK (
+        status IN ('PENDING', 'APPROVED', 'REJECTED', 'RESOLVED', 'CANCELLED')
+    )
+);
+
+CREATE INDEX idx_teacher_absences_teacher_period
+    ON teacher_absences(teacher_id, start_date, end_date);
+
+CREATE INDEX idx_teacher_absences_status
+    ON teacher_absences(status);
+
+CREATE TABLE teacher_absence_decisions (
+    id BIGSERIAL PRIMARY KEY,
+    absence_id BIGINT NOT NULL REFERENCES teacher_absences(id) ON DELETE CASCADE,
+    base_rule_slot_id BIGINT NOT NULL REFERENCES schedule_rule_slots(id),
+    lesson_date DATE NOT NULL,
+    resolution VARCHAR(30) NOT NULL,
+    decision_status VARCHAR(20) NOT NULL,
+    schedule_override_id BIGINT REFERENCES schedule_overrides(id) ON DELETE SET NULL,
+    comment TEXT,
+    decided_by BIGINT REFERENCES users(id),
+    decided_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT uq_teacher_absence_decision_lesson UNIQUE (
+        absence_id,
+        base_rule_slot_id,
+        lesson_date
+    ),
+    CONSTRAINT chk_teacher_absence_decision_resolution CHECK (
+        resolution IN ('REPLACE_TEACHER', 'MOVE_TIME', 'CHANGE_CLASSROOM', 'CANCEL', 'REJECT')
+    ),
+    CONSTRAINT chk_teacher_absence_decision_status CHECK (
+        decision_status IN ('APPLIED', 'REJECTED')
+    )
+);
+
+CREATE INDEX idx_teacher_absence_decisions_absence
+    ON teacher_absence_decisions(absence_id, lesson_date);
+
+COMMENT ON TABLE teacher_absences IS 'Временные отсутствия преподавателей с согласованием кафедрой';
+COMMENT ON COLUMN teacher_absences.status IS 'PENDING, APPROVED, REJECTED, RESOLVED или CANCELLED';
+COMMENT ON TABLE teacher_absence_decisions IS 'Журнал применённых и отклонённых решений мастера замены';
+COMMENT ON COLUMN teacher_absence_decisions.resolution IS 'Выбранный способ разрешения затронутого занятия';
+
+-- ==========================================
+-- Пожелания и заявки преподавателей
+-- ==========================================
+CREATE TABLE teacher_preferences (
+    id BIGSERIAL PRIMARY KEY,
+    teacher_id BIGINT NOT NULL REFERENCES users(id),
+    semester_id BIGINT NOT NULL REFERENCES semesters(id),
+    preference_type VARCHAR(30) NOT NULL,
+    day_of_week SMALLINT,
+    time_slot_id BIGINT REFERENCES time_slots(id),
+    preference_date DATE,
+    comment TEXT,
+    status VARCHAR(20) NOT NULL,
+    requested_by BIGINT REFERENCES users(id),
+    reviewed_by BIGINT REFERENCES users(id),
+    review_comment TEXT,
+    reviewed_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT chk_teacher_preferences_type CHECK (
+        preference_type IN (
+            'HARD_UNAVAILABLE',
+            'SOFT_PREFERRED',
+            'SOFT_UNWANTED',
+            'CONSECUTIVE',
+            'NO_GAPS'
+        )
+    ),
+    CONSTRAINT chk_teacher_preferences_status CHECK (
+        status IN ('PENDING', 'APPROVED', 'REJECTED', 'CANCELLED')
+    ),
+    CONSTRAINT chk_teacher_preferences_day CHECK (
+        day_of_week IS NULL OR day_of_week BETWEEN 1 AND 7
+    ),
+    CONSTRAINT chk_teacher_preferences_payload CHECK (
+        (
+            preference_type = 'HARD_UNAVAILABLE'
+            AND (
+                (preference_date IS NOT NULL AND day_of_week IS NULL AND time_slot_id IS NULL)
+                OR
+                (preference_date IS NULL AND day_of_week IS NOT NULL AND time_slot_id IS NOT NULL)
+            )
+        )
+        OR
+        (
+            preference_type IN ('SOFT_PREFERRED', 'SOFT_UNWANTED')
+            AND preference_date IS NULL
+            AND day_of_week IS NOT NULL
+            AND time_slot_id IS NOT NULL
+        )
+        OR
+        (
+            preference_type IN ('CONSECUTIVE', 'NO_GAPS')
+            AND preference_date IS NULL
+            AND day_of_week IS NULL
+            AND time_slot_id IS NULL
+        )
+    ),
+    CONSTRAINT chk_teacher_preferences_comment CHECK (
+        comment IS NULL OR length(trim(comment)) BETWEEN 1 AND 2000
+    )
+);
+
+CREATE INDEX idx_teacher_preferences_teacher_semester
+    ON teacher_preferences(teacher_id, semester_id, status);
+
+CREATE INDEX idx_teacher_preferences_slot
+    ON teacher_preferences(semester_id, day_of_week, time_slot_id)
+    WHERE status = 'APPROVED';
+
+CREATE INDEX idx_teacher_preferences_date
+    ON teacher_preferences(teacher_id, preference_date)
+    WHERE status = 'APPROVED' AND preference_date IS NOT NULL;
+
+CREATE TABLE teacher_change_requests (
+    id BIGSERIAL PRIMARY KEY,
+    teacher_id BIGINT NOT NULL REFERENCES users(id),
+    base_rule_slot_id BIGINT NOT NULL REFERENCES schedule_rule_slots(id),
+    lesson_date DATE NOT NULL,
+    request_type VARCHAR(30) NOT NULL,
+    target_lesson_date DATE,
+    requested_time_slot_id BIGINT REFERENCES time_slots(id),
+    requested_classroom_id BIGINT REFERENCES classrooms(id),
+    reason TEXT NOT NULL,
+    status VARCHAR(20) NOT NULL,
+    reviewed_by BIGINT REFERENCES users(id),
+    review_comment TEXT,
+    reviewed_at TIMESTAMPTZ,
+    applied_override_id BIGINT REFERENCES schedule_overrides(id) ON DELETE SET NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT chk_teacher_change_requests_type CHECK (
+        request_type IN ('MOVE', 'CHANGE_CLASSROOM', 'CANCEL')
+    ),
+    CONSTRAINT chk_teacher_change_requests_status CHECK (
+        status IN ('PENDING', 'APPROVED', 'REJECTED', 'CANCELLED')
+    ),
+    CONSTRAINT chk_teacher_change_requests_reason CHECK (
+        length(trim(reason)) BETWEEN 1 AND 2000
+    ),
+    CONSTRAINT chk_teacher_change_requests_payload CHECK (
+        (
+            request_type = 'MOVE'
+            AND requested_time_slot_id IS NOT NULL
+            AND requested_classroom_id IS NULL
+        )
+        OR
+        (
+            request_type = 'CHANGE_CLASSROOM'
+            AND target_lesson_date IS NULL
+            AND requested_time_slot_id IS NULL
+            AND requested_classroom_id IS NOT NULL
+        )
+        OR
+        (
+            request_type = 'CANCEL'
+            AND target_lesson_date IS NULL
+            AND requested_time_slot_id IS NULL
+            AND requested_classroom_id IS NULL
+        )
+    )
+);
+
+CREATE INDEX idx_teacher_change_requests_teacher
+    ON teacher_change_requests(teacher_id, created_at DESC);
+
+CREATE INDEX idx_teacher_change_requests_status
+    ON teacher_change_requests(status, created_at);
+
+CREATE UNIQUE INDEX uq_teacher_change_requests_pending_lesson
+    ON teacher_change_requests(base_rule_slot_id, lesson_date)
+    WHERE status = 'PENDING';
+
+CREATE TABLE teacher_change_request_history (
+    id BIGSERIAL PRIMARY KEY,
+    request_id BIGINT NOT NULL REFERENCES teacher_change_requests(id) ON DELETE CASCADE,
+    status VARCHAR(20) NOT NULL,
+    comment TEXT,
+    actor_id BIGINT REFERENCES users(id),
+    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT chk_teacher_change_request_history_status CHECK (
+        status IN ('PENDING', 'APPROVED', 'REJECTED', 'CANCELLED')
+    )
+);
+
+CREATE INDEX idx_teacher_change_request_history_request
+    ON teacher_change_request_history(request_id, created_at, id);
+
+COMMENT ON TABLE teacher_preferences IS 'Согласуемые ограничения и пожелания преподавателей на семестр';
+COMMENT ON COLUMN teacher_preferences.preference_type IS 'Строгая недоступность, мягкое пожелание или пожелание к компактности расписания';
+COMMENT ON TABLE teacher_change_requests IS 'Заявки преподавателей на перенос, смену аудитории или отмену опубликованного занятия';
+COMMENT ON TABLE teacher_change_request_history IS 'Неизменяемая история статусов и комментариев по заявке преподавателя';
+
+-- ==========================================
+-- Черновики, версии, публикация и аудит расписания
+-- ==========================================
+CREATE TABLE schedule_versions (
+    id BIGSERIAL PRIMARY KEY,
+    semester_id BIGINT NOT NULL REFERENCES semesters(id) ON DELETE CASCADE,
+    version_number INT NOT NULL,
+    name VARCHAR(160) NOT NULL,
+    status VARCHAR(20) NOT NULL,
+    based_on_version_id BIGINT REFERENCES schedule_versions(id) ON DELETE SET NULL,
+    restored_from_version_id BIGINT REFERENCES schedule_versions(id) ON DELETE SET NULL,
+    change_reason TEXT,
+    created_by BIGINT REFERENCES users(id),
+    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    published_by BIGINT REFERENCES users(id),
+    published_at TIMESTAMPTZ,
+    archived_at TIMESTAMPTZ,
+    CONSTRAINT uq_schedule_versions_number UNIQUE (semester_id, version_number),
+    CONSTRAINT chk_schedule_versions_number CHECK (version_number > 0),
+    CONSTRAINT chk_schedule_versions_name CHECK (length(trim(name)) BETWEEN 1 AND 160),
+    CONSTRAINT chk_schedule_versions_status CHECK (status IN ('DRAFT', 'PUBLISHED', 'ARCHIVED')),
+    CONSTRAINT chk_schedule_versions_publish_fields CHECK (
+        status <> 'PUBLISHED' OR published_at IS NOT NULL
+    )
+);
+
+CREATE UNIQUE INDEX uq_schedule_versions_published_semester
+    ON schedule_versions(semester_id)
+    WHERE status = 'PUBLISHED';
+
+CREATE INDEX idx_schedule_versions_semester_history
+    ON schedule_versions(semester_id, version_number DESC);
+
+INSERT INTO schedule_versions (
+    semester_id,
+    version_number,
+    name,
+    status,
+    created_at,
+    published_at
+)
+SELECT
+    semester.id,
+    1,
+    'Опубликованная версия 1',
+    'PUBLISHED',
+    CURRENT_TIMESTAMP,
+    CURRENT_TIMESTAMP
+FROM semesters semester;
+
+ALTER TABLE schedule_rules
+    ADD COLUMN schedule_version_id BIGINT;
+
+UPDATE schedule_rules rule
+SET schedule_version_id = version.id,
+    version_group_id = COALESCE(rule.version_group_id, rule.id)
+FROM schedule_versions version
+WHERE version.semester_id = rule.semester_id
+  AND version.status = 'PUBLISHED';
+
+ALTER TABLE schedule_rules
+    ALTER COLUMN schedule_version_id SET NOT NULL,
+    ADD CONSTRAINT fk_schedule_rules_version
+        FOREIGN KEY (schedule_version_id) REFERENCES schedule_versions(id) ON DELETE CASCADE;
+
+CREATE INDEX idx_schedule_rules_version
+    ON schedule_rules(schedule_version_id, status);
+
+CREATE UNIQUE INDEX uq_schedule_rules_version_group
+    ON schedule_rules(schedule_version_id, version_group_id)
+    WHERE version_group_id IS NOT NULL;
+
+CREATE TABLE schedule_version_history (
+    id BIGSERIAL PRIMARY KEY,
+    version_id BIGINT NOT NULL REFERENCES schedule_versions(id) ON DELETE CASCADE,
+    action VARCHAR(30) NOT NULL,
+    actor_id BIGINT REFERENCES users(id),
+    reason TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT chk_schedule_version_history_action CHECK (
+        action IN ('CREATED', 'PUBLISHED', 'ARCHIVED', 'RESTORED')
+    ),
+    CONSTRAINT chk_schedule_version_history_reason CHECK (
+        reason IS NULL OR length(trim(reason)) BETWEEN 1 AND 2000
+    )
+);
+
+CREATE INDEX idx_schedule_version_history_version
+    ON schedule_version_history(version_id, created_at DESC, id DESC);
+
+INSERT INTO schedule_version_history (version_id, action, reason, created_at)
+SELECT id, 'CREATED', 'Начальная версия расписания', created_at
+FROM schedule_versions;
+
+INSERT INTO schedule_version_history (version_id, action, reason, created_at)
+SELECT id, 'PUBLISHED', 'Начальная публикация расписания', published_at
+FROM schedule_versions;
+
+COMMENT ON TABLE schedule_versions IS 'Изолированные черновики и опубликованные версии правил расписания';
+COMMENT ON COLUMN schedule_versions.status IS 'DRAFT, PUBLISHED или ARCHIVED';
+COMMENT ON COLUMN schedule_versions.based_on_version_id IS 'Версия, из которой был скопирован черновик';
+COMMENT ON COLUMN schedule_versions.restored_from_version_id IS 'Предыдущая опубликованная версия при восстановлении';
+COMMENT ON COLUMN schedule_rules.schedule_version_id IS 'Версия расписания, которой принадлежит правило';
+COMMENT ON COLUMN schedule_rules.version_group_id IS 'Стабильный идентификатор правила между версиями';
+COMMENT ON TABLE schedule_version_history IS 'Неизменяемый журнал создания, публикации, архивации и восстановления версий';
--- a/backend/src/main/resources/db/migration/V2__backfill_default_theory_periods.sql
+++ b/backend/src/main/resources/db/migration/V2__backfill_default_theory_periods.sql
@@ -0,0 +1,24 @@
+INSERT INTO academic_calendar_periods (
+    calendar_id,
+    course_number,
+    start_date,
+    end_date,
+    activity_type_id
+)
+SELECT
+    calendar.id,
+    course.course_number,
+    academic_year.start_date,
+    academic_year.end_date,
+    theory_activity.id
+FROM academic_calendars calendar
+JOIN academic_years academic_year
+    ON academic_year.id = calendar.academic_year_id
+JOIN academic_calendar_activity_types theory_activity
+    ON theory_activity.code = 'Т'
+CROSS JOIN LATERAL GENERATE_SERIES(1, calendar.course_count) AS course(course_number)
+WHERE NOT EXISTS (
+    SELECT 1
+    FROM academic_calendar_periods existing_period
+    WHERE existing_period.calendar_id = calendar.id
+);
--- a/backend/src/test/java/com/magistr/app/controller/AcademicCalendarControllerTest.java
+++ b/backend/src/test/java/com/magistr/app/controller/AcademicCalendarControllerTest.java
@@ -1,18 +1,17 @@
 package com.magistr.app.controller;

 import com.magistr.app.dto.AcademicCalendarDto;
+import com.magistr.app.dto.AcademicCalendarGridDayDto;
 import com.magistr.app.model.AcademicCalendar;
+import com.magistr.app.model.AcademicCalendarActivityType;
+import com.magistr.app.model.AcademicCalendarPeriod;
 import com.magistr.app.model.AcademicYear;
 import com.magistr.app.model.EducationForm;
 import com.magistr.app.model.Speciality;
 import com.magistr.app.model.SpecialtyProfile;
-import com.magistr.app.repository.AcademicCalendarDayRepository;
+import com.magistr.app.repository.AcademicCalendarPeriodRepository;
 import com.magistr.app.repository.AcademicCalendarRepository;
 import com.magistr.app.repository.AcademicCalendarSubjectRepository;
-import com.magistr.app.repository.AcademicYearRepository;
-import com.magistr.app.repository.EducationFormRepository;
-import com.magistr.app.repository.SpecialtiesRepository;
-import com.magistr.app.repository.SpecialtyProfileRepository;
 import com.magistr.app.repository.SubjectRepository;
 import com.magistr.app.service.AcademicCalendarGridService;
 import com.magistr.app.service.AcademicStructureService;
@@ -20,22 +19,18 @@ import com.magistr.app.service.ScheduleGeneratorService;
 import org.junit.jupiter.api.Test;

 import java.time.LocalDate;
-import java.util.Optional;
+import java.util.List;

 import static org.assertj.core.api.Assertions.assertThat;
-import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;

 class AcademicCalendarControllerTest {

    @Test
-    void createCalendarBuildsTitleWithoutClientValue() {
+    void createCalendarReturnsCalendarCreatedByTransactionalService() {
        AcademicCalendarRepository calendarRepository = mock(AcademicCalendarRepository.class);
-        AcademicYearRepository academicYearRepository = mock(AcademicYearRepository.class);
-        SpecialtiesRepository specialtiesRepository = mock(SpecialtiesRepository.class);
-        SpecialtyProfileRepository profileRepository = mock(SpecialtyProfileRepository.class);
-        EducationFormRepository educationFormRepository = mock(EducationFormRepository.class);
+        AcademicStructureService academicStructureService = mock(AcademicStructureService.class);

        AcademicYear year = new AcademicYear();
        year.setId(1L);
@@ -51,26 +46,6 @@ class AcademicCalendarControllerTest {
        studyForm.setId(4L);
        studyForm.setName("Очная");

-        when(academicYearRepository.findById(1L)).thenReturn(Optional.of(year));
-        when(specialtiesRepository.findById(2L)).thenReturn(Optional.of(speciality));
-        when(profileRepository.findById(3L)).thenReturn(Optional.of(profile));
-        when(educationFormRepository.findById(4L)).thenReturn(Optional.of(studyForm));
-        when(calendarRepository.save(any(AcademicCalendar.class)))
-                .thenAnswer(invocation -> invocation.getArgument(0));
-
-        AcademicCalendarController controller = new AcademicCalendarController(
-                calendarRepository,
-                mock(AcademicCalendarDayRepository.class),
-                academicYearRepository,
-                specialtiesRepository,
-                profileRepository,
-                educationFormRepository,
-                mock(SubjectRepository.class),
-                mock(AcademicCalendarSubjectRepository.class),
-                mock(AcademicCalendarGridService.class),
-                mock(ScheduleGeneratorService.class),
-                mock(AcademicStructureService.class)
-        );
        AcademicCalendarDto request = new AcademicCalendarDto(
                null,
                null,
@@ -87,12 +62,97 @@ class AcademicCalendarControllerTest {
                null,
                4
        );
+        AcademicCalendar saved = new AcademicCalendar();
+        saved.setTitle("09.03.04 — Разработка ПО — Очная — 2026-2027");
+        saved.setAcademicYear(year);
+        saved.setSpeciality(speciality);
+        saved.setSpecialtyProfile(profile);
+        saved.setStudyForm(studyForm);
+        saved.setCourseCount(4);
+        when(academicStructureService.createCalendar(request)).thenReturn(saved);
+
+        AcademicCalendarController controller = new AcademicCalendarController(
+                calendarRepository,
+                mock(AcademicCalendarPeriodRepository.class),
+                mock(SubjectRepository.class),
+                mock(AcademicCalendarSubjectRepository.class),
+                mock(AcademicCalendarGridService.class),
+                mock(ScheduleGeneratorService.class),
+                academicStructureService
+        );

        var response = controller.createCalendar(request);

        assertThat(response.getStatusCode().value()).isEqualTo(200);
        assertThat(response.getBody()).isInstanceOf(AcademicCalendarDto.class);
        assertThat(((AcademicCalendarDto) response.getBody()).title())
-                .isEqualTo("09.03.04 — Разработка ПО — Очная — 2026-2027");
+                .isEqualTo(saved.getTitle());
+    }
+
+    @Test
+    void getGridExpandsPeriodIntoDailyRows() {
+        AcademicCalendarRepository calendarRepository = mock(AcademicCalendarRepository.class);
+        AcademicCalendarPeriodRepository periodRepository = mock(AcademicCalendarPeriodRepository.class);
+
+        AcademicYear year = new AcademicYear();
+        year.setId(1L);
+        year.setStartDate(LocalDate.of(2026, 9, 1));
+        year.setEndDate(LocalDate.of(2027, 6, 30));
+
+        AcademicCalendar calendar = new AcademicCalendar();
+        calendar.setId(10L);
+        calendar.setAcademicYear(year);
+
+        AcademicCalendarActivityType activityType = new AcademicCalendarActivityType();
+        activityType.setId(20L);
+        activityType.setCode("Т");
+        activityType.setName("Теоретическое обучение");
+        activityType.setAllowSchedule(true);
+
+        AcademicCalendarPeriod period = new AcademicCalendarPeriod();
+        period.setId(30L);
+        period.setAcademicCalendar(calendar);
+        period.setCourseNumber(1);
+        period.setStartDate(LocalDate.of(2026, 9, 6));
+        period.setEndDate(LocalDate.of(2026, 9, 8));
+        period.setActivityType(activityType);
+
+        when(calendarRepository.existsById(10L)).thenReturn(true);
+        when(periodRepository.findByCalendarIdWithActivity(10L)).thenReturn(List.of(period));
+
+        AcademicCalendarController controller = new AcademicCalendarController(
+                calendarRepository,
+                periodRepository,
+                mock(SubjectRepository.class),
+                mock(AcademicCalendarSubjectRepository.class),
+                mock(AcademicCalendarGridService.class),
+                mock(ScheduleGeneratorService.class),
+                mock(AcademicStructureService.class)
+        );
+
+        var response = controller.getGrid(10L);
+
+        assertThat(response.getStatusCode().value()).isEqualTo(200);
+        assertThat(response.getBody()).isInstanceOf(List.class);
+        @SuppressWarnings("unchecked")
+        List<AcademicCalendarGridDayDto> rows = (List<AcademicCalendarGridDayDto>) response.getBody();
+        assertThat(rows)
+                .extracting(AcademicCalendarGridDayDto::date)
+                .containsExactly(
+                        LocalDate.of(2026, 9, 6),
+                        LocalDate.of(2026, 9, 7),
+                        LocalDate.of(2026, 9, 8)
+                );
+        assertThat(rows)
+                .extracting(AcademicCalendarGridDayDto::weekNumber)
+                .containsExactly(1, 2, 2);
+        assertThat(rows)
+                .extracting(AcademicCalendarGridDayDto::dayOfWeek)
+                .containsExactly(7, 1, 2);
+        assertThat(rows)
+                .allSatisfy(row -> {
+                    assertThat(row.id()).isEqualTo(30L);
+                    assertThat(row.activityTypeId()).isEqualTo(20L);
+                });
    }
 }
--- a/backend/src/test/java/com/magistr/app/controller/ScheduleQualityControllerTest.java
+++ b/backend/src/test/java/com/magistr/app/controller/ScheduleQualityControllerTest.java
@@ -0,0 +1,71 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.dto.ScheduleQualityAnalysisDto;
+import com.magistr.app.model.ScheduleVersionStatus;
+import com.magistr.app.service.ScheduleQualityService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.time.LocalDate;
+import java.util.List;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standaloneSetup;
+
+class ScheduleQualityControllerTest {
+
+    private ScheduleQualityService service;
+    private MockMvc mockMvc;
+
+    @BeforeEach
+    void setUp() {
+        service = mock(ScheduleQualityService.class);
+        mockMvc = standaloneSetup(new ScheduleQualityController(service))
+                .setControllerAdvice(new GlobalExceptionHandler())
+                .build();
+    }
+
+    @Test
+    void returnsExplainableSemesterScore() throws Exception {
+        when(service.analyze(7L, 12L)).thenReturn(new ScheduleQualityAnalysisDto(
+                7L,
+                "2026/2027 · осенний семестр",
+                LocalDate.of(2026, 9, 1),
+                LocalDate.of(2026, 12, 31),
+                82,
+                18,
+                420,
+                3,
+                false,
+                List.of(new ScheduleQualityAnalysisDto.Metric(
+                        "GROUP_GAPS",
+                        "Окна у групп",
+                        3,
+                        "окон",
+                        6,
+                        "Свободные пары между занятиями"
+                )),
+                List.of(),
+                12L,
+                2,
+                "Черновик новой сетки",
+                ScheduleVersionStatus.DRAFT
+        ));
+
+        mockMvc.perform(get("/api/edu-office/schedule/quality")
+                        .param("semesterId", "7")
+                        .param("versionId", "12"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.score").value(82))
+                .andExpect(jsonPath("$.scheduleVersionStatus").value("DRAFT"))
+                .andExpect(jsonPath("$.metrics[0].code").value("GROUP_GAPS"));
+
+        verify(service).analyze(7L, 12L);
+    }
+}
--- a/backend/src/test/java/com/magistr/app/controller/ScheduleRuleAdminControllerTest.java
+++ b/backend/src/test/java/com/magistr/app/controller/ScheduleRuleAdminControllerTest.java
@@ -118,7 +118,8 @@ class ScheduleRuleAdminControllerTest {
                1,
                List.of(3L),
                List.of("Группа"),
-                List.of()
+                List.of(),
+                9L
        );
    }

@@ -127,6 +128,7 @@ class ScheduleRuleAdminControllerTest {
                {
                  "subjectId": 1,
                  "semesterId": 2,
+                  "scheduleVersionId": 9,
                  "lectureAcademicHours": 2,
                  "laboratoryAcademicHours": 0,
                  "practiceAcademicHours": 0,
--- a/backend/src/test/java/com/magistr/app/controller/TeacherAbsenceControllerTest.java
+++ b/backend/src/test/java/com/magistr/app/controller/TeacherAbsenceControllerTest.java
@@ -0,0 +1,136 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.dto.TeacherAbsenceDto;
+import com.magistr.app.dto.TeacherAbsenceWizardDto;
+import com.magistr.app.service.TeacherAbsenceService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.util.List;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standaloneSetup;
+
+class TeacherAbsenceControllerTest {
+
+    private TeacherAbsenceService service;
+    private MockMvc mockMvc;
+
+    @BeforeEach
+    void setUp() {
+        service = mock(TeacherAbsenceService.class);
+        mockMvc = standaloneSetup(new TeacherAbsenceController(service))
+                .setControllerAdvice(new GlobalExceptionHandler())
+                .build();
+    }
+
+    @Test
+    void createsAbsenceWithRussianReason() throws Exception {
+        when(service.create(any())).thenReturn(absence("APPROVED"));
+
+        mockMvc.perform(post("/api/teacher-absences")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("""
+                                {
+                                  "teacherId": 11,
+                                  "startDate": "2026-09-10",
+                                  "endDate": "2026-09-12",
+                                  "reason": "Командировка"
+                                }
+                                """))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.teacherName").value("Иванов Иван Иванович"))
+                .andExpect(jsonPath("$.status").value("APPROVED"));
+    }
+
+    @Test
+    void returnsWizardWithAffectedLessonsAndJournal() throws Exception {
+        TeacherAbsenceWizardDto wizard = new TeacherAbsenceWizardDto(
+                absence("APPROVED"),
+                List.of(new TeacherAbsenceWizardDto.AffectedLesson(
+                        501L,
+                        LocalDate.of(2026, 9, 10),
+                        java.time.LocalTime.of(9, 0),
+                        java.time.LocalTime.of(10, 30),
+                        40L,
+                        "Базы данных",
+                        3L,
+                        "Лекция",
+                        8L,
+                        "101",
+                        List.of("ИВТ-21"),
+                        null,
+                        null,
+                        List.of(),
+                        List.of(),
+                        List.of(),
+                        true
+                )),
+                List.of()
+        );
+        when(service.getWizard(101L)).thenReturn(wizard);
+
+        mockMvc.perform(get("/api/teacher-absences/101/wizard"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.lessons[0].subjectName").value("Базы данных"))
+                .andExpect(jsonPath("$.lessons[0].cancellationAvailable").value(true));
+
+        verify(service).getWizard(101L);
+    }
+
+    @Test
+    void appliesSelectedDecisionsAsBatch() throws Exception {
+        TeacherAbsenceWizardDto wizard = new TeacherAbsenceWizardDto(
+                absence("RESOLVED"),
+                List.of(),
+                List.of()
+        );
+        when(service.resolve(eq(101L), any())).thenReturn(wizard);
+
+        mockMvc.perform(post("/api/teacher-absences/101/resolve")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("""
+                                {
+                                  "decisions": [{
+                                    "baseRuleSlotId": 501,
+                                    "lessonDate": "2026-09-10",
+                                    "resolution": "CANCEL"
+                                  }]
+                                }
+                                """))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.absence.status").value("RESOLVED"));
+    }
+
+    private TeacherAbsenceDto absence(String status) {
+        return new TeacherAbsenceDto(
+                101L,
+                11L,
+                "Иванов Иван Иванович",
+                7L,
+                LocalDate.of(2026, 9, 10),
+                LocalDate.of(2026, 9, 12),
+                "Командировка",
+                status,
+                1L,
+                1L,
+                null,
+                Instant.parse("2026-08-06T10:00:00Z"),
+                Instant.parse("2026-08-06T10:00:00Z"),
+                Instant.parse("2026-08-06T10:00:00Z"),
+                0
+        );
+    }
+}
--- a/backend/src/test/java/com/magistr/app/controller/TeacherChangeRequestControllerTest.java
+++ b/backend/src/test/java/com/magistr/app/controller/TeacherChangeRequestControllerTest.java
@@ -0,0 +1,90 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.dto.TeacherChangeRequestDto;
+import com.magistr.app.service.TeacherChangeRequestService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.List;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standaloneSetup;
+
+class TeacherChangeRequestControllerTest {
+
+    private TeacherChangeRequestService service;
+    private MockMvc mockMvc;
+
+    @BeforeEach
+    void setUp() {
+        service = mock(TeacherChangeRequestService.class);
+        mockMvc = standaloneSetup(new TeacherChangeRequestController(service))
+                .setControllerAdvice(new GlobalExceptionHandler())
+                .build();
+    }
+
+    @Test
+    void createsMoveRequestWithRussianReason() throws Exception {
+        when(service.create(any())).thenReturn(request("PENDING"));
+
+        mockMvc.perform(post("/api/teacher-change-requests")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("""
+                                {
+                                  "baseRuleSlotId": 40,
+                                  "lessonDate": "2026-09-14",
+                                  "requestType": "MOVE",
+                                  "targetLessonDate": "2026-09-16",
+                                  "requestedTimeSlotId": 4,
+                                  "reason": "Участие в конференции"
+                                }
+                                """))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.status").value("PENDING"))
+                .andExpect(jsonPath("$.reason").value("Участие в конференции"));
+    }
+
+    @Test
+    void approvesRequestAndReturnsAppliedOverride() throws Exception {
+        when(service.review(eq(12L), any())).thenReturn(request("APPROVED"));
+
+        mockMvc.perform(post("/api/teacher-change-requests/12/review")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("""
+                                {"approved": true, "comment": "Свободный слот подтверждён"}
+                                """))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.status").value("APPROVED"))
+                .andExpect(jsonPath("$.appliedOverrideId").value(77));
+
+        verify(service).review(eq(12L), any());
+    }
+
+    private TeacherChangeRequestDto request(String status) {
+        Instant now = Instant.parse("2026-08-11T10:00:00Z");
+        return new TeacherChangeRequestDto(
+                12L, 11L, "Иванов Иван Иванович", 7L, 40L,
+                LocalDate.of(2026, 9, 14), "Базы данных", "Лекция", List.of("ИВТ-21"),
+                2L, 1, LocalTime.of(9, 0), LocalTime.of(10, 30), 8L, "101",
+                "MOVE", LocalDate.of(2026, 9, 16), 4L, 2,
+                LocalTime.of(10, 40), LocalTime.of(12, 10), null, null,
+                "Участие в конференции", status, status.equals("APPROVED") ? 1L : null,
+                status.equals("APPROVED") ? "Свободный слот подтверждён" : null,
+                status.equals("APPROVED") ? now : null, status.equals("APPROVED") ? 77L : null,
+                now, now,
+                List.of(new TeacherChangeRequestDto.HistoryItem(1L, status, "Комментарий", 1L, now))
+        );
+    }
+}
--- a/backend/src/test/java/com/magistr/app/controller/TeacherPreferenceControllerTest.java
+++ b/backend/src/test/java/com/magistr/app/controller/TeacherPreferenceControllerTest.java
@@ -0,0 +1,77 @@
+package com.magistr.app.controller;
+
+import com.magistr.app.dto.TeacherPreferenceDto;
+import com.magistr.app.service.TeacherPreferenceService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.List;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standaloneSetup;
+
+class TeacherPreferenceControllerTest {
+
+    private TeacherPreferenceService service;
+    private MockMvc mockMvc;
+
+    @BeforeEach
+    void setUp() {
+        service = mock(TeacherPreferenceService.class);
+        mockMvc = standaloneSetup(new TeacherPreferenceController(service))
+                .setControllerAdvice(new GlobalExceptionHandler())
+                .build();
+    }
+
+    @Test
+    void returnsApprovedPreferencesForSemester() throws Exception {
+        when(service.getAll(5L, "APPROVED")).thenReturn(List.of(preference("APPROVED")));
+
+        mockMvc.perform(get("/api/teacher-preferences")
+                        .param("semesterId", "5")
+                        .param("status", "APPROVED"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$[0].preferenceType").value("SOFT_PREFERRED"))
+                .andExpect(jsonPath("$[0].teacherName").value("Иванов Иван Иванович"));
+    }
+
+    @Test
+    void reviewsPendingPreference() throws Exception {
+        when(service.review(eq(9L), any())).thenReturn(preference("APPROVED"));
+
+        mockMvc.perform(post("/api/teacher-preferences/9/review")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("""
+                                {"approved": true, "comment": "Учтено при составлении расписания"}
+                                """))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.status").value("APPROVED"));
+
+        verify(service).review(eq(9L), any());
+    }
+
+    private TeacherPreferenceDto preference(String status) {
+        Instant now = Instant.parse("2026-08-11T10:00:00Z");
+        return new TeacherPreferenceDto(
+                9L, 11L, "Иванов Иван Иванович", 7L, 5L, "2026/2027", "AUTUMN",
+                LocalDate.of(2026, 9, 1), LocalDate.of(2026, 12, 31),
+                "SOFT_PREFERRED", 1, "Понедельник", 3L, 2,
+                LocalTime.of(10, 40), LocalTime.of(12, 10), null, null, status,
+                11L, status.equals("APPROVED") ? 1L : null, null,
+                status.equals("APPROVED") ? now : null, now, now
+        );
+    }
+}
--- a/backend/src/test/java/com/magistr/app/controller/WorkloadControllerTest.java
+++ b/backend/src/test/java/com/magistr/app/controller/WorkloadControllerTest.java
@@ -82,6 +82,36 @@ class WorkloadControllerTest {
                .containsOnly(1L);
    }

+    @Test
+    void departmentTeacherWorkloadUsesRequestedAdditionalDepartment() {
+        ScheduleQueryService scheduleQueryService = mock(ScheduleQueryService.class);
+        TeacherDepartmentService teacherDepartmentService = mock(TeacherDepartmentService.class);
+        DepartmentRepository departmentRepository = mock(DepartmentRepository.class);
+        LocalDate startDate = LocalDate.of(2026, 5, 1);
+        LocalDate endDate = LocalDate.of(2026, 5, 31);
+        RenderedLessonDto lesson = lesson(10L, "Петров Пётр", LocalDate.of(2026, 5, 15), 1L);
+        when(scheduleQueryService.searchForAggregation(7L, null, startDate, endDate))
+                .thenReturn(List.of(lesson));
+        when(departmentRepository.findById(7L))
+                .thenReturn(Optional.of(new Department(7L, "Кафедра ИБ", 7L)));
+        WorkloadController controller = new WorkloadController(
+                scheduleQueryService,
+                mock(ClassroomRepository.class),
+                departmentRepository,
+                teacherDepartmentService
+        );
+        authenticate(Role.DEPARTMENT, 7L);
+
+        List<WorkloadSummaryDto> result = controller.teacherWorkload(startDate, endDate, null);
+
+        assertThat(result).singleElement().satisfies(item -> {
+            assertThat(item.id()).isEqualTo(10L);
+            assertThat(item.departmentId()).isEqualTo(7L);
+            assertThat(item.lessonCount()).isEqualTo(1L);
+        });
+        verifyNoInteractions(teacherDepartmentService);
+    }
+
    @Test
    void freeClassroomsSkipsNullAvailabilityWithoutNpe() {
        ScheduleQueryService scheduleQueryService = mock(ScheduleQueryService.class);
--- a/backend/src/test/java/com/magistr/app/migration/AcademicCalendarDefaultTheoryPeriodMigrationIntegrationTest.java
+++ b/backend/src/test/java/com/magistr/app/migration/AcademicCalendarDefaultTheoryPeriodMigrationIntegrationTest.java
@@ -0,0 +1,148 @@
+package com.magistr.app.migration;
+
+import org.flywaydb.core.Flyway;
+import org.flywaydb.core.api.MigrationVersion;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.PostgreSQLContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@Testcontainers
+@DisplayName("Миграция начальных периодов календарного графика")
+class AcademicCalendarDefaultTheoryPeriodMigrationIntegrationTest {
+
+    @Container
+    static final PostgreSQLContainer<?> POSTGRES =
+            new PostgreSQLContainer<>(com.magistr.app.testing.TestContainerImages.POSTGRES);
+
+    @Test
+    @DisplayName("V2 заполняет кодом Т только полностью пустые графики")
+    void migrationBackfillsOnlyEmptyCalendars() throws SQLException {
+        Flyway baseline = flyway("1");
+        baseline.clean();
+        baseline.migrate();
+
+        long emptyCalendarId;
+        long configuredCalendarId;
+        try (Connection connection = POSTGRES.createConnection("")) {
+            emptyCalendarId = insertCalendarFromSeed(connection, "Пустой график для V2", 3);
+            configuredCalendarId = insertCalendarFromSeed(connection, "Настроенный график для V2", 2);
+            insertConfiguredPeriod(connection, configuredCalendarId);
+        }
+
+        Flyway allMigrations = flyway(null);
+        allMigrations.migrate();
+
+        assertThat(allMigrations.info().current()).isNotNull();
+        assertThat(allMigrations.info().current().getVersion().getVersion()).isEqualTo("2");
+
+        try (Connection connection = POSTGRES.createConnection("")) {
+            assertThat(readSummary(connection, emptyCalendarId))
+                    .isEqualTo(new PeriodSummary(3, 1, 3, true));
+            assertThat(readSummary(connection, configuredCalendarId))
+                    .isEqualTo(new PeriodSummary(1, 1, 1, false));
+        }
+    }
+
+    private Flyway flyway(String targetVersion) {
+        var configuration = Flyway.configure()
+                .dataSource(POSTGRES.getJdbcUrl(), POSTGRES.getUsername(), POSTGRES.getPassword())
+                .locations("classpath:db/migration")
+                .cleanDisabled(false);
+        if (targetVersion != null) {
+            configuration.target(MigrationVersion.fromVersion(targetVersion));
+        }
+        return configuration.load();
+    }
+
+    private long insertCalendarFromSeed(Connection connection,
+                                        String title,
+                                        int courseCount) throws SQLException {
+        try (PreparedStatement statement = connection.prepareStatement("""
+                INSERT INTO academic_calendars (
+                    title,
+                    academic_year_id,
+                    specialty_id,
+                    specialty_profile_id,
+                    study_form_id,
+                    course_count
+                )
+                SELECT ?, academic_year_id, specialty_id, specialty_profile_id, study_form_id, ?
+                FROM academic_calendars
+                ORDER BY id
+                LIMIT 1
+                RETURNING id
+                """)) {
+            statement.setString(1, title);
+            statement.setInt(2, courseCount);
+            try (ResultSet resultSet = statement.executeQuery()) {
+                assertThat(resultSet.next()).isTrue();
+                return resultSet.getLong(1);
+            }
+        }
+    }
+
+    private void insertConfiguredPeriod(Connection connection, long calendarId) throws SQLException {
+        try (PreparedStatement statement = connection.prepareStatement("""
+                INSERT INTO academic_calendar_periods (
+                    calendar_id,
+                    course_number,
+                    start_date,
+                    end_date,
+                    activity_type_id
+                )
+                SELECT calendar.id, 1, academic_year.start_date, academic_year.start_date, activity.id
+                FROM academic_calendars calendar
+                JOIN academic_years academic_year ON academic_year.id = calendar.academic_year_id
+                JOIN academic_calendar_activity_types activity ON activity.code = 'К'
+                WHERE calendar.id = ?
+                """)) {
+            statement.setLong(1, calendarId);
+            assertThat(statement.executeUpdate()).isEqualTo(1);
+        }
+    }
+
+    private PeriodSummary readSummary(Connection connection, long calendarId) throws SQLException {
+        try (PreparedStatement statement = connection.prepareStatement("""
+                SELECT
+                    COUNT(*),
+                    MIN(period.course_number),
+                    MAX(period.course_number),
+                    BOOL_AND(
+                        activity.code = 'Т'
+                        AND period.start_date = academic_year.start_date
+                        AND period.end_date = academic_year.end_date
+                    )
+                FROM academic_calendar_periods period
+                JOIN academic_calendars calendar ON calendar.id = period.calendar_id
+                JOIN academic_years academic_year ON academic_year.id = calendar.academic_year_id
+                JOIN academic_calendar_activity_types activity ON activity.id = period.activity_type_id
+                WHERE period.calendar_id = ?
+                """)) {
+            statement.setLong(1, calendarId);
+            try (ResultSet resultSet = statement.executeQuery()) {
+                assertThat(resultSet.next()).isTrue();
+                return new PeriodSummary(
+                        resultSet.getInt(1),
+                        resultSet.getInt(2),
+                        resultSet.getInt(3),
+                        resultSet.getBoolean(4)
+                );
+            }
+        }
+    }
+
+    private record PeriodSummary(int count,
+                                 int minCourse,
+                                 int maxCourse,
+                                 boolean fullYearTheory) {
+    }
+}
--- a/backend/src/test/java/com/magistr/app/migration/AcademicCalendarWeekNumberBaselineIntegrationTest.java
+++ b/backend/src/test/java/com/magistr/app/migration/AcademicCalendarWeekNumberBaselineIntegrationTest.java
@@ -1,6 +1,7 @@
 package com.magistr.app.migration;

 import org.flywaydb.core.Flyway;
+import org.flywaydb.core.api.MigrationVersion;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.testcontainers.containers.PostgreSQLContainer;
@@ -30,6 +31,7 @@ class AcademicCalendarWeekNumberBaselineIntegrationTest {
        Flyway flyway = Flyway.configure()
                .dataSource(POSTGRES.getJdbcUrl(), POSTGRES.getUsername(), POSTGRES.getPassword())
                .locations("classpath:db/migration")
+                .target(MigrationVersion.fromVersion("1"))
                .cleanDisabled(false)
                .load();

--- a/backend/src/test/java/com/magistr/app/migration/AcademicStructureInvariantIntegrationTest.java
+++ b/backend/src/test/java/com/magistr/app/migration/AcademicStructureInvariantIntegrationTest.java
@@ -92,9 +92,14 @@ class AcademicStructureInvariantIntegrationTest {
                    "сохранённая сетка выходит за новые измерения"
            );
            assertSqlState(
-                    () -> insertOutOfRangeCalendarDay(connection, calendarId),
+                    () -> insertOutOfRangeCalendarPeriod(connection, calendarId),
                    "23514",
-                    "Строка сетки выходит за измерения календарного графика"
+                    "Период активности выходит за измерения календарного графика"
+            );
+            assertSqlState(
+                    () -> insertOverlappingCalendarPeriod(connection, calendarId),
+                    "23P01",
+                    "ex_calendar_periods_no_overlap"
            );
            assertSqlState(
                    () -> insertOutOfRangeCalendarSubject(connection, calendarId),
@@ -479,16 +484,15 @@ class AcademicStructureInvariantIntegrationTest {
        }
    }

-    private void insertOutOfRangeCalendarDay(Connection connection, long calendarId) throws SQLException {
+    private void insertOutOfRangeCalendarPeriod(Connection connection, long calendarId) throws SQLException {
        try (PreparedStatement statement = connection.prepareStatement("""
-                INSERT INTO academic_calendar_days (
+                INSERT INTO academic_calendar_periods (
                    calendar_id,
                    course_number,
-                    date,
-                    week_number,
-                    day_of_week,
+                    start_date,
+                    end_date,
                    activity_type_id
-                ) VALUES (?, 5, DATE '2025-09-01', 1, 1, (
+                ) VALUES (?, 5, DATE '2025-09-01', DATE '2025-09-01', (
                    SELECT id FROM academic_calendar_activity_types WHERE code = 'Т'
                ))
                """)) {
@@ -497,6 +501,23 @@ class AcademicStructureInvariantIntegrationTest {
        }
    }

+    private void insertOverlappingCalendarPeriod(Connection connection, long calendarId) throws SQLException {
+        try (PreparedStatement statement = connection.prepareStatement("""
+                INSERT INTO academic_calendar_periods (
+                    calendar_id,
+                    course_number,
+                    start_date,
+                    end_date,
+                    activity_type_id
+                ) VALUES (?, 1, DATE '2025-09-15', DATE '2025-09-30', (
+                    SELECT id FROM academic_calendar_activity_types WHERE code = 'К'
+                ))
+                """)) {
+            statement.setLong(1, calendarId);
+            statement.executeUpdate();
+        }
+    }
+
    private void insertOutOfRangeCalendarSubject(Connection connection, long calendarId) throws SQLException {
        try (PreparedStatement statement = connection.prepareStatement("""
                INSERT INTO academic_calendar_subjects (calendar_id, semester_number, subject_id)
--- a/backend/src/test/java/com/magistr/app/migration/ScheduleRuleHoursMigrationIntegrationTest.java
+++ b/backend/src/test/java/com/magistr/app/migration/ScheduleRuleHoursMigrationIntegrationTest.java
@@ -44,6 +44,13 @@ class ScheduleRuleHoursMigrationIntegrationTest {
        try (Connection connection = POSTGRES.createConnection("")) {
            SeedIds seedIds = loadSeedIds(connection);
            long rulesBeforeInsert = queryLong(connection, "SELECT count(*) FROM schedule_rules");
+            assertThat(queryLong(connection, "SELECT count(*) FROM schedule_rules WHERE schedule_version_id IS NULL"))
+                    .as("Все исходные правила должны принадлежать опубликованной версии")
+                    .isZero();
+            assertThat(queryLong(connection, "SELECT count(*) FROM schedule_versions WHERE status = 'PUBLISHED'"))
+                    .as("V1 должна создать по одной опубликованной версии на семестр")
+                    .isEqualTo(queryLong(connection, "SELECT count(*) FROM semesters"));
+            assertSecondPublishedVersionRejected(connection, seedIds.semesterId());

            insertScheduleRule(connection, seedIds, 2, 4, 6);

@@ -83,7 +90,8 @@ class ScheduleRuleHoursMigrationIntegrationTest {
    private SeedIds loadSeedIds(Connection connection) throws SQLException {
        return new SeedIds(
                queryLong(connection, "SELECT id FROM subjects ORDER BY id LIMIT 1"),
-                queryLong(connection, "SELECT id FROM semesters ORDER BY id LIMIT 1")
+                queryLong(connection, "SELECT id FROM semesters ORDER BY id LIMIT 1"),
+                queryLong(connection, "SELECT id FROM schedule_versions ORDER BY id LIMIT 1")
        );
    }

@@ -98,19 +106,21 @@ class ScheduleRuleHoursMigrationIntegrationTest {
                INSERT INTO schedule_rules (
                    subject_id,
                    semester_id,
+                    schedule_version_id,
                    lecture_academic_hours,
                    laboratory_academic_hours,
                    practice_academic_hours,
                    lecture_start_week,
                    laboratory_start_week,
                    practice_start_week
-                ) VALUES (?, ?, ?, ?, ?, 1, 1, 1)
+                ) VALUES (?, ?, ?, ?, ?, ?, 1, 1, 1)
                """)) {
            statement.setLong(1, seedIds.subjectId());
            statement.setLong(2, seedIds.semesterId());
-            statement.setInt(3, lectureHours);
-            statement.setInt(4, laboratoryHours);
-            statement.setInt(5, practiceHours);
+            statement.setLong(3, seedIds.scheduleVersionId());
+            statement.setInt(4, lectureHours);
+            statement.setInt(5, laboratoryHours);
+            statement.setInt(6, practiceHours);
            statement.executeUpdate();
        }
    }
@@ -143,6 +153,23 @@ class ScheduleRuleHoursMigrationIntegrationTest {
                .contains(HOURS_CONSTRAINT);
    }

+    private void assertSecondPublishedVersionRejected(Connection connection, long semesterId) {
+        Throwable failure = catchThrowable(() -> {
+            try (PreparedStatement statement = connection.prepareStatement("""
+                    INSERT INTO schedule_versions (
+                        semester_id, version_number, name, status, published_at
+                    ) VALUES (?, 99, 'Недопустимая вторая публикация', 'PUBLISHED', CURRENT_TIMESTAMP)
+                    """)) {
+                statement.setLong(1, semesterId);
+                statement.executeUpdate();
+            }
+        });
+        assertThat(failure)
+                .as("В одном семестре не может быть двух опубликованных версий")
+                .isInstanceOf(SQLException.class);
+        assertThat(((SQLException) failure).getSQLState()).isEqualTo("23505");
+    }
+
    private void assertExactSlotDuplicateRejected(Connection connection) {
        Throwable failure = catchThrowable(() -> duplicateExistingSlot(connection));

@@ -201,6 +228,6 @@ class ScheduleRuleHoursMigrationIntegrationTest {
        }
    }

-    private record SeedIds(long subjectId, long semesterId) {
+    private record SeedIds(long subjectId, long semesterId, long scheduleVersionId) {
    }
 }
--- a/backend/src/test/java/com/magistr/app/migration/TeacherDepartmentInvariantIntegrationTest.java
+++ b/backend/src/test/java/com/magistr/app/migration/TeacherDepartmentInvariantIntegrationTest.java
@@ -45,13 +45,16 @@ class TeacherDepartmentInvariantIntegrationTest {
            long teacherId = seedTeacherId(connection);
            long firstDepartmentId = queryLong(connection, "SELECT min(id) FROM departments");
            long secondDepartmentId = queryLong(connection, "SELECT max(id) FROM departments");
-            updateOpenPrimaryEnd(connection, teacherId, LocalDate.of(2026, 7, 31));
+            LocalDate initialStart = openPrimaryStart(connection, teacherId);
+            LocalDate initialEnd = initialStart.plusDays(30);
+            LocalDate transferStart = initialEnd.plusDays(1);
+            updateOpenPrimaryEnd(connection, teacherId, initialEnd);

            insertAssignment(
                    connection,
                    teacherId,
                    secondDepartmentId,
-                    LocalDate.of(2026, 8, 1),
+                    transferStart,
                    null,
                    true
            );
@@ -59,7 +62,7 @@ class TeacherDepartmentInvariantIntegrationTest {
                    connection,
                    teacherId,
                    firstDepartmentId,
-                    LocalDate.of(2026, 8, 1),
+                    transferStart,
                    null,
                    false
            );
@@ -69,8 +72,8 @@ class TeacherDepartmentInvariantIntegrationTest {
                            connection,
                            teacherId,
                            firstDepartmentId,
-                            LocalDate.of(2026, 8, 15),
-                            LocalDate.of(2026, 9, 1),
+                            transferStart.plusDays(14),
+                            transferStart.plusDays(31),
                            true
                    ),
                    "23P01",
@@ -94,11 +97,14 @@ class TeacherDepartmentInvariantIntegrationTest {
        long teacherId;
        long firstDepartmentId;
        long secondDepartmentId;
+        LocalDate firstCandidateStart;
        try (Connection connection = POSTGRES.createConnection("")) {
            teacherId = seedTeacherId(connection);
            firstDepartmentId = queryLong(connection, "SELECT min(id) FROM departments");
            secondDepartmentId = queryLong(connection, "SELECT max(id) FROM departments");
-            updateOpenPrimaryEnd(connection, teacherId, LocalDate.of(2089, 12, 31));
+            LocalDate initialStart = openPrimaryStart(connection, teacherId);
+            updateOpenPrimaryEnd(connection, teacherId, initialStart.plusDays(30));
+            firstCandidateStart = initialStart.plusDays(31);
        }

        ExecutorService executor = Executors.newFixedThreadPool(2);
@@ -109,16 +115,16 @@ class TeacherDepartmentInvariantIntegrationTest {
                    executor.submit(() -> concurrentInsert(
                            teacherId,
                            firstDepartmentId,
-                            LocalDate.of(2090, 1, 1),
-                            LocalDate.of(2090, 12, 31),
+                            firstCandidateStart,
+                            firstCandidateStart.plusDays(364),
                            ready,
                            start
                    )),
                    executor.submit(() -> concurrentInsert(
                            teacherId,
                            secondDepartmentId,
-                            LocalDate.of(2090, 6, 1),
-                            LocalDate.of(2091, 5, 31),
+                            firstCandidateStart.plusDays(151),
+                            firstCandidateStart.plusDays(515),
                            ready,
                            start
                    ))
@@ -186,6 +192,22 @@ class TeacherDepartmentInvariantIntegrationTest {
        );
    }

+    private LocalDate openPrimaryStart(Connection connection, long teacherId) throws SQLException {
+        try (PreparedStatement statement = connection.prepareStatement("""
+                SELECT valid_from
+                FROM teacher_department_assignments
+                WHERE teacher_id = ?
+                  AND is_primary = TRUE
+                  AND valid_to IS NULL
+                """)) {
+            statement.setLong(1, teacherId);
+            try (ResultSet resultSet = statement.executeQuery()) {
+                assertThat(resultSet.next()).isTrue();
+                return resultSet.getDate(1).toLocalDate();
+            }
+        }
+    }
+
    private void updateOpenPrimaryEnd(Connection connection,
                                      long teacherId,
                                      LocalDate validTo) throws SQLException {
--- a/backend/src/test/java/com/magistr/app/migration/TeacherPreferencesMigrationIntegrationTest.java
+++ b/backend/src/test/java/com/magistr/app/migration/TeacherPreferencesMigrationIntegrationTest.java
@@ -0,0 +1,85 @@
+package com.magistr.app.migration;
+
+import com.magistr.app.testing.TestContainerImages;
+import org.flywaydb.core.Flyway;
+import org.flywaydb.core.api.MigrationVersion;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.PostgreSQLContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.catchThrowable;
+
+@Testcontainers
+@DisplayName("Преподавательские процессы в базовой схеме")
+class TeacherPreferencesMigrationIntegrationTest {
+
+    @Container
+    static final PostgreSQLContainer<?> POSTGRES = new PostgreSQLContainer<>(TestContainerImages.POSTGRES);
+
+    @Test
+    @DisplayName("V1 содержит таблицы прежних V2/V3 и отклоняет противоречивое пожелание")
+    void migrationCreatesWorkflowTablesAndConstraints() throws SQLException {
+        Flyway flyway = Flyway.configure()
+                .dataSource(POSTGRES.getJdbcUrl(), POSTGRES.getUsername(), POSTGRES.getPassword())
+                .locations("classpath:db/migration")
+                .target(MigrationVersion.fromVersion("1"))
+                .cleanDisabled(false)
+                .load();
+        flyway.clean();
+        flyway.migrate();
+
+        assertThat(flyway.info().current().getVersion().getVersion()).isEqualTo("1");
+        try (Connection connection = POSTGRES.createConnection("")) {
+            assertThat(queryLong(connection, """
+                    SELECT count(*)
+                    FROM information_schema.tables
+                    WHERE table_schema = 'public'
+                      AND table_name IN (
+                        'teacher_absences',
+                        'teacher_absence_decisions',
+                        'teacher_preferences',
+                        'teacher_change_requests',
+                        'teacher_change_request_history'
+                      )
+                    """)).isEqualTo(5L);
+
+            long teacherId = queryLong(connection, "SELECT id FROM users WHERE role = 'TEACHER' ORDER BY id LIMIT 1");
+            long semesterId = queryLong(connection, "SELECT id FROM semesters ORDER BY id LIMIT 1");
+            long timeSlotId = queryLong(connection, "SELECT id FROM time_slots ORDER BY id LIMIT 1");
+
+            Throwable failure = catchThrowable(() -> {
+                try (PreparedStatement statement = connection.prepareStatement("""
+                        INSERT INTO teacher_preferences (
+                            teacher_id, semester_id, preference_type,
+                            day_of_week, time_slot_id, preference_date, status
+                        ) VALUES (?, ?, 'SOFT_PREFERRED', 1, ?, CURRENT_DATE, 'PENDING')
+                        """)) {
+                    statement.setLong(1, teacherId);
+                    statement.setLong(2, semesterId);
+                    statement.setLong(3, timeSlotId);
+                    statement.executeUpdate();
+                }
+            });
+
+            assertThat(failure).isInstanceOf(SQLException.class);
+            assertThat(((SQLException) failure).getSQLState()).isEqualTo("23514");
+            assertThat(failure.getMessage()).contains("chk_teacher_preferences_payload");
+        }
+    }
+
+    private long queryLong(Connection connection, String sql) throws SQLException {
+        try (PreparedStatement statement = connection.prepareStatement(sql);
+             ResultSet resultSet = statement.executeQuery()) {
+            assertThat(resultSet.next()).isTrue();
+            return resultSet.getLong(1);
+        }
+    }
+}
--- a/backend/src/test/java/com/magistr/app/service/AcademicCalendarGridServiceIntegrationTest.java
+++ b/backend/src/test/java/com/magistr/app/service/AcademicCalendarGridServiceIntegrationTest.java
@@ -1,8 +1,8 @@
 package com.magistr.app.service;

 import com.magistr.app.dto.AcademicCalendarGridDayDto;
-import com.magistr.app.model.AcademicCalendarDay;
-import com.magistr.app.repository.AcademicCalendarDayRepository;
+import com.magistr.app.model.AcademicCalendarPeriod;
+import com.magistr.app.repository.AcademicCalendarPeriodRepository;
 import org.junit.jupiter.api.Test;
 import org.springframework.aop.support.AopUtils;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -110,12 +110,13 @@ class AcademicCalendarGridServiceIntegrationTest {
        assertThat(fingerprint(calendarId)).isEqualTo(before);
        assertThat(queryLong("""
                SELECT count(*)
-                FROM academic_calendar_days day
-                WHERE day.calendar_id = ?
-                  AND day.course_number = 1
-                  AND day.date = ?
-                  AND day.activity_type_id = ?
-                """, calendarId, yearStart, holidayActivityId)).isZero();
+                FROM academic_calendar_periods period
+                WHERE period.calendar_id = ?
+                  AND period.course_number = 1
+                  AND period.start_date <= ?
+                  AND period.end_date >= ?
+                  AND period.activity_type_id = ?
+                """, calendarId, yearStart, yearStart, holidayActivityId)).isZero();
        verify(scheduleGeneratorService, never()).clearCache();

        AcademicCalendarGridDayDto secondValid = row(
@@ -131,15 +132,26 @@ class AcademicCalendarGridServiceIntegrationTest {
        assertThat(after).isNotEqualTo(before);
        assertThat(queryLong("""
                SELECT count(*)
-                FROM academic_calendar_days day
-                WHERE day.calendar_id = ?
+                FROM academic_calendar_periods period
+                WHERE period.calendar_id = ?
                  AND (
-                    (day.course_number = 1 AND day.date = ? AND day.activity_type_id = ?)
-                    OR
-                    (day.course_number = 1 AND day.date = ? AND day.activity_type_id = ?)
+                    (
+                        period.course_number = 1
+                        AND period.start_date = ?
+                        AND period.end_date = ?
+                        AND period.activity_type_id = ?
                    )
-                """, calendarId, yearStart, holidayActivityId,
-                yearStart.plusDays(1), theoryActivityId)).isEqualTo(2L);
+                    OR
+                    (
+                        period.course_number = 1
+                        AND period.start_date = ?
+                        AND period.end_date = ?
+                        AND period.activity_type_id = ?
+                    )
+                  )
+                """, calendarId,
+                yearStart, yearStart, holidayActivityId,
+                yearStart.plusDays(1), yearStart.plusDays(1), theoryActivityId)).isEqualTo(2L);
        verify(scheduleGeneratorService, times(1)).clearCache();
    }

@@ -149,16 +161,15 @@ class AcademicCalendarGridServiceIntegrationTest {
                    count(*) AS row_count,
                    md5(string_agg(
                        concat_ws('|',
-                            day.course_number::text,
-                            day.date::text,
-                            day.week_number::text,
-                            day.day_of_week::text,
-                            day.activity_type_id::text
+                            period.course_number::text,
+                            period.start_date::text,
+                            period.end_date::text,
+                            period.activity_type_id::text
                        ),
-                        E'\\n' ORDER BY day.course_number, day.date, day.id
+                        E'\\n' ORDER BY period.course_number, period.start_date, period.id
                    )) AS content_hash
-                FROM academic_calendar_days day
-                WHERE day.calendar_id = ?
+                FROM academic_calendar_periods period
+                WHERE period.calendar_id = ?
                """, (result, rowNumber) -> new GridFingerprint(
                result.getLong("row_count"),
                result.getString("content_hash")
@@ -196,8 +207,8 @@ class AcademicCalendarGridServiceIntegrationTest {

    @SpringBootConfiguration
    @EnableAutoConfiguration
-    @EntityScan(basePackageClasses = AcademicCalendarDay.class)
-    @EnableJpaRepositories(basePackageClasses = AcademicCalendarDayRepository.class)
+    @EntityScan(basePackageClasses = AcademicCalendarPeriod.class)
+    @EnableJpaRepositories(basePackageClasses = AcademicCalendarPeriodRepository.class)
    @Import({AcademicCalendarGridService.class, TestDependencies.class})
    static class TestApplication {
    }
--- a/backend/src/test/java/com/magistr/app/service/AcademicCalendarGridServiceTest.java
+++ b/backend/src/test/java/com/magistr/app/service/AcademicCalendarGridServiceTest.java
@@ -3,10 +3,10 @@ package com.magistr.app.service;
 import com.magistr.app.dto.AcademicCalendarGridDayDto;
 import com.magistr.app.model.AcademicCalendar;
 import com.magistr.app.model.AcademicCalendarActivityType;
-import com.magistr.app.model.AcademicCalendarDay;
+import com.magistr.app.model.AcademicCalendarPeriod;
 import com.magistr.app.model.AcademicYear;
 import com.magistr.app.repository.AcademicCalendarActivityTypeRepository;
-import com.magistr.app.repository.AcademicCalendarDayRepository;
+import com.magistr.app.repository.AcademicCalendarPeriodRepository;
 import com.magistr.app.repository.AcademicCalendarRepository;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -41,7 +41,7 @@ class AcademicCalendarGridServiceTest {
    @Mock
    private AcademicCalendarRepository calendarRepository;
    @Mock
-    private AcademicCalendarDayRepository calendarDayRepository;
+    private AcademicCalendarPeriodRepository calendarPeriodRepository;
    @Mock
    private AcademicCalendarActivityTypeRepository activityTypeRepository;
    @Mock
@@ -73,7 +73,7 @@ class AcademicCalendarGridServiceTest {

        service = new AcademicCalendarGridService(
                calendarRepository,
-                calendarDayRepository,
+                calendarPeriodRepository,
                activityTypeRepository,
                scheduleGeneratorService
        );
@@ -180,17 +180,18 @@ class AcademicCalendarGridServiceTest {
        service.replaceGrid(CALENDAR_ID, List.of(first, second));

        @SuppressWarnings("unchecked")
-        ArgumentCaptor<List<AcademicCalendarDay>> replacementCaptor = ArgumentCaptor.forClass(List.class);
-        InOrder mutationOrder = inOrder(calendarDayRepository, scheduleGeneratorService);
-        mutationOrder.verify(calendarDayRepository).deleteByCalendarId(CALENDAR_ID);
-        mutationOrder.verify(calendarDayRepository).flush();
-        mutationOrder.verify(calendarDayRepository).saveAll(replacementCaptor.capture());
-        mutationOrder.verify(calendarDayRepository).flush();
+        ArgumentCaptor<List<AcademicCalendarPeriod>> replacementCaptor = ArgumentCaptor.forClass(List.class);
+        InOrder mutationOrder = inOrder(calendarPeriodRepository, scheduleGeneratorService);
+        mutationOrder.verify(calendarPeriodRepository).deleteByCalendarId(CALENDAR_ID);
+        mutationOrder.verify(calendarPeriodRepository).flush();
+        mutationOrder.verify(calendarPeriodRepository).saveAll(replacementCaptor.capture());
+        mutationOrder.verify(calendarPeriodRepository).flush();
        mutationOrder.verify(scheduleGeneratorService).clearCache();

-        assertThat(replacementCaptor.getValue())
-                .extracting(AcademicCalendarDay::getDate)
-                .containsExactly(YEAR_START, YEAR_START.plusDays(1));
+        assertThat(replacementCaptor.getValue()).singleElement().satisfies(period -> {
+            assertThat(period.getStartDate()).isEqualTo(YEAR_START);
+            assertThat(period.getEndDate()).isEqualTo(YEAR_START.plusDays(1));
+        });
        assertThat(replacementCaptor.getValue())
                .allSatisfy(day -> {
                    assertThat(day.getAcademicCalendar().getId()).isEqualTo(CALENDAR_ID);
@@ -212,11 +213,22 @@ class AcademicCalendarGridServiceTest {
        ));

        @SuppressWarnings("unchecked")
-        ArgumentCaptor<List<AcademicCalendarDay>> replacementCaptor = ArgumentCaptor.forClass(List.class);
-        verify(calendarDayRepository).saveAll(replacementCaptor.capture());
+        ArgumentCaptor<List<AcademicCalendarPeriod>> replacementCaptor = ArgumentCaptor.forClass(List.class);
+        verify(calendarPeriodRepository).saveAll(replacementCaptor.capture());
        assertThat(replacementCaptor.getValue())
-                .extracting(AcademicCalendarDay::getWeekNumber)
-                .containsExactly(1, 1, 2, 3);
+                .extracting(AcademicCalendarPeriod::getStartDate)
+                .containsExactly(
+                        yearStart,
+                        LocalDate.of(2026, 9, 6),
+                        LocalDate.of(2026, 9, 14)
+                );
+        assertThat(replacementCaptor.getValue())
+                .extracting(AcademicCalendarPeriod::getEndDate)
+                .containsExactly(
+                        yearStart,
+                        LocalDate.of(2026, 9, 7),
+                        LocalDate.of(2026, 9, 14)
+                );
    }

    @Test
@@ -233,11 +245,22 @@ class AcademicCalendarGridServiceTest {
        ));

        @SuppressWarnings("unchecked")
-        ArgumentCaptor<List<AcademicCalendarDay>> replacementCaptor = ArgumentCaptor.forClass(List.class);
-        verify(calendarDayRepository).saveAll(replacementCaptor.capture());
+        ArgumentCaptor<List<AcademicCalendarPeriod>> replacementCaptor = ArgumentCaptor.forClass(List.class);
+        verify(calendarPeriodRepository).saveAll(replacementCaptor.capture());
        assertThat(replacementCaptor.getValue())
-                .extracting(AcademicCalendarDay::getWeekNumber)
-                .containsExactly(1, 1, 2, 3);
+                .extracting(AcademicCalendarPeriod::getStartDate)
+                .containsExactly(
+                        yearStart,
+                        LocalDate.of(2027, 9, 5),
+                        LocalDate.of(2027, 9, 13)
+                );
+        assertThat(replacementCaptor.getValue())
+                .extracting(AcademicCalendarPeriod::getEndDate)
+                .containsExactly(
+                        yearStart,
+                        LocalDate.of(2027, 9, 6),
+                        LocalDate.of(2027, 9, 13)
+                );
    }

    private AcademicCalendarGridDayDto validRow(LocalDate date, int weekNumber, int dayOfWeek) {
@@ -263,10 +286,10 @@ class AcademicCalendarGridServiceTest {
    }

    private void verifyNoMutation() {
-        verify(calendarDayRepository, never()).deleteByCalendarId(any());
-        verify(calendarDayRepository, never()).flush();
-        verify(calendarDayRepository, never()).save(any());
-        verify(calendarDayRepository, never()).saveAll(any());
+        verify(calendarPeriodRepository, never()).deleteByCalendarId(any());
+        verify(calendarPeriodRepository, never()).flush();
+        verify(calendarPeriodRepository, never()).save(any());
+        verify(calendarPeriodRepository, never()).saveAll(any());
        verify(scheduleGeneratorService, never()).clearCache();
    }
 }
--- a/backend/src/test/java/com/magistr/app/service/AcademicPeriodServiceTest.java
+++ b/backend/src/test/java/com/magistr/app/service/AcademicPeriodServiceTest.java
@@ -3,9 +3,13 @@ package com.magistr.app.service;
 import com.magistr.app.dto.AcademicYearDto;
 import com.magistr.app.dto.SemesterDto;
 import com.magistr.app.model.AcademicYear;
+import com.magistr.app.model.ScheduleVersion;
+import com.magistr.app.model.ScheduleVersionStatus;
 import com.magistr.app.model.Semester;
 import com.magistr.app.model.SemesterType;
 import com.magistr.app.repository.AcademicYearRepository;
+import com.magistr.app.repository.ScheduleVersionHistoryRepository;
+import com.magistr.app.repository.ScheduleVersionRepository;
 import com.magistr.app.repository.SemesterRepository;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -42,6 +46,10 @@ class AcademicPeriodServiceTest {
    private SemesterRepository semesterRepository;
    @Mock
    private ScheduleGeneratorService scheduleGeneratorService;
+    @Mock
+    private ScheduleVersionRepository scheduleVersionRepository;
+    @Mock
+    private ScheduleVersionHistoryRepository scheduleVersionHistoryRepository;

    private AcademicPeriodService service;
    private AcademicYear year;
@@ -51,13 +59,17 @@ class AcademicPeriodServiceTest {
        service = new AcademicPeriodService(
                academicYearRepository,
                semesterRepository,
-                scheduleGeneratorService
+                scheduleGeneratorService,
+                scheduleVersionRepository,
+                scheduleVersionHistoryRepository
        );
        year = year();
        when(academicYearRepository.saveAndFlush(any(AcademicYear.class)))
                .thenAnswer(invocation -> invocation.getArgument(0));
        when(semesterRepository.saveAndFlush(any(Semester.class)))
                .thenAnswer(invocation -> invocation.getArgument(0));
+        when(scheduleVersionRepository.saveAndFlush(any(ScheduleVersion.class)))
+                .thenAnswer(invocation -> invocation.getArgument(0));
    }

    @Test
@@ -158,6 +170,12 @@ class AcademicPeriodServiceTest {

        assertThat(saved.getStartDate()).isEqualTo(LocalDate.of(2027, 2, 1));
        assertThat(saved.getAcademicYear()).isSameAs(year);
+        verify(scheduleVersionRepository).saveAndFlush(org.mockito.ArgumentMatchers.argThat(version ->
+                version.getSemester() == saved
+                        && version.getStatus() == ScheduleVersionStatus.PUBLISHED
+                        && "Основное расписание".equals(version.getName())
+        ));
+        verify(scheduleVersionHistoryRepository, org.mockito.Mockito.times(2)).save(any());
        verify(scheduleGeneratorService).clearCache();
    }

--- a/backend/src/test/java/com/magistr/app/service/AcademicStructureServiceTest.java
+++ b/backend/src/test/java/com/magistr/app/service/AcademicStructureServiceTest.java
@@ -4,13 +4,16 @@ import com.magistr.app.dto.AcademicCalendarDto;
 import com.magistr.app.dto.CreateGroupRequest;
 import com.magistr.app.dto.GroupCalendarAssignmentDto;
 import com.magistr.app.model.AcademicCalendar;
+import com.magistr.app.model.AcademicCalendarActivityType;
+import com.magistr.app.model.AcademicCalendarPeriod;
 import com.magistr.app.model.AcademicYear;
 import com.magistr.app.model.EducationForm;
 import com.magistr.app.model.Speciality;
 import com.magistr.app.model.SpecialtyProfile;
 import com.magistr.app.model.StudentGroup;
 import com.magistr.app.model.StudentGroupCalendarAssignment;
-import com.magistr.app.repository.AcademicCalendarDayRepository;
+import com.magistr.app.repository.AcademicCalendarActivityTypeRepository;
+import com.magistr.app.repository.AcademicCalendarPeriodRepository;
 import com.magistr.app.repository.AcademicCalendarRepository;
 import com.magistr.app.repository.AcademicCalendarSubjectRepository;
 import com.magistr.app.repository.AcademicYearRepository;
@@ -23,6 +26,7 @@ import com.magistr.app.repository.SubgroupRepository;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 import org.mockito.junit.jupiter.MockitoSettings;
@@ -54,7 +58,9 @@ class AcademicStructureServiceTest {
    @Mock
    private AcademicCalendarRepository calendarRepository;
    @Mock
-    private AcademicCalendarDayRepository calendarDayRepository;
+    private AcademicCalendarPeriodRepository calendarPeriodRepository;
+    @Mock
+    private AcademicCalendarActivityTypeRepository activityTypeRepository;
    @Mock
    private AcademicCalendarSubjectRepository calendarSubjectRepository;
    @Mock
@@ -87,7 +93,8 @@ class AcademicStructureServiceTest {
    void setUp() {
        service = new AcademicStructureService(
                calendarRepository,
-                calendarDayRepository,
+                calendarPeriodRepository,
+                activityTypeRepository,
                calendarSubjectRepository,
                academicYearRepository,
                specialtiesRepository,
@@ -118,12 +125,54 @@ class AcademicStructureServiceTest {
        when(subgroupRepository.sumActiveStudentCapacityByGroupId(GROUP_ID)).thenReturn(0L);
        when(calendarRepository.saveAndFlush(any(AcademicCalendar.class)))
                .thenAnswer(invocation -> invocation.getArgument(0));
+        AcademicCalendarActivityType theoryActivity = new AcademicCalendarActivityType();
+        theoryActivity.setId(80L);
+        theoryActivity.setCode("Т");
+        theoryActivity.setName("Теоретическое обучение");
+        theoryActivity.setAllowSchedule(true);
+        when(activityTypeRepository.findByCode("Т")).thenReturn(Optional.of(theoryActivity));
        when(groupRepository.saveAndFlush(any(StudentGroup.class)))
                .thenAnswer(invocation -> invocation.getArgument(0));
        when(assignmentRepository.saveAndFlush(any(StudentGroupCalendarAssignment.class)))
                .thenAnswer(invocation -> invocation.getArgument(0));
    }

+    @Test
+    void createsCalendarWithTheoryPeriodForEveryCourseAcrossWholeAcademicYear() {
+        AcademicCalendar saved = service.createCalendar(calendarRequest(3, FORM_ID));
+
+        @SuppressWarnings("unchecked")
+        ArgumentCaptor<List<AcademicCalendarPeriod>> periodsCaptor = ArgumentCaptor.forClass(List.class);
+        verify(calendarPeriodRepository).saveAll(periodsCaptor.capture());
+
+        assertThat(saved.getTitle())
+                .isEqualTo("09.03.01 — Без профиля — Бакалавриат — 2025-2026");
+        assertThat(periodsCaptor.getValue())
+                .extracting(AcademicCalendarPeriod::getCourseNumber)
+                .containsExactly(1, 2, 3);
+        assertThat(periodsCaptor.getValue()).allSatisfy(period -> {
+            assertThat(period.getAcademicCalendar()).isSameAs(saved);
+            assertThat(period.getStartDate()).isEqualTo(academicYear.getStartDate());
+            assertThat(period.getEndDate()).isEqualTo(academicYear.getEndDate());
+            assertThat(period.getActivityType().getCode()).isEqualTo("Т");
+            assertThat(period.getActivityType().getAllowSchedule()).isTrue();
+        });
+        verify(scheduleGeneratorService).clearCache();
+    }
+
+    @Test
+    void rejectsCalendarCreationWhenSchedulingTheoryActivityIsMissing() {
+        when(activityTypeRepository.findByCode("Т")).thenReturn(Optional.empty());
+
+        assertThatThrownBy(() -> service.createCalendar(calendarRequest(4, FORM_ID)))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessage("Код активности «Т», разрешающий обычные занятия, не найден");
+
+        verify(calendarRepository, never()).saveAndFlush(any());
+        verify(calendarPeriodRepository, never()).saveAll(any());
+        verify(scheduleGeneratorService, never()).clearCache();
+    }
+
    @Test
    void rejectsCalendarDimensionChangeAndKeepsEntityUnchanged() {
        when(assignmentRepository.findByCalendarIdWithDetails(CALENDAR_ID))
@@ -142,7 +191,7 @@ class AcademicStructureServiceTest {

    @Test
    void rejectsCourseCountBelowExistingGrid() {
-        when(calendarDayRepository.existsByAcademicCalendarIdAndCourseNumberGreaterThan(
+        when(calendarPeriodRepository.existsByAcademicCalendarIdAndCourseNumberGreaterThan(
                CALENDAR_ID, 3)).thenReturn(true);

        assertThatThrownBy(() -> service.updateCalendar(
--- a/backend/src/test/java/com/magistr/app/service/ScheduleGenerationQueryCountTest.java
+++ b/backend/src/test/java/com/magistr/app/service/ScheduleGenerationQueryCountTest.java
@@ -32,7 +32,7 @@ class ScheduleGenerationQueryCountTest {
        SemesterRepository semesterRepository = mock(SemesterRepository.class);
        StudentGroupCalendarAssignmentRepository assignmentRepository =
                mock(StudentGroupCalendarAssignmentRepository.class);
-        AcademicCalendarDayRepository calendarDayRepository = mock(AcademicCalendarDayRepository.class);
+        AcademicCalendarPeriodRepository calendarPeriodRepository = mock(AcademicCalendarPeriodRepository.class);
        ScheduleRuleRepository ruleRepository = mock(ScheduleRuleRepository.class);
        TimeSlotDateAssignmentRepository dateAssignmentRepository = mock(TimeSlotDateAssignmentRepository.class);
        TimeSlotScopeRepository scopeRepository = mock(TimeSlotScopeRepository.class);
@@ -47,9 +47,9 @@ class ScheduleGenerationQueryCountTest {
        List<StudentGroupCalendarAssignment> assignments = groups.stream()
                .map(group -> assignment(group, academicYear, calendar))
                .toList();
-        List<AcademicCalendarDay> calendarDays = START_DATE.datesUntil(END_DATE.plusDays(1))
-                .map(date -> calendarDay(calendar, date))
-                .toList();
+        List<AcademicCalendarPeriod> calendarPeriods = List.of(
+                calendarPeriod(calendar, START_DATE, END_DATE)
+        );
        List<ScheduleRule> rules = IntStream.rangeClosed(1, RULE_COUNT)
                .mapToObj(index -> rule(index, semester, groups))
                .toList();
@@ -63,8 +63,12 @@ class ScheduleGenerationQueryCountTest {
                .thenReturn(List.of(semester));
        when(assignmentRepository.findForScheduleBatch(anyCollection(), anyCollection()))
                .thenReturn(assignments);
-        when(calendarDayRepository.findForScheduleBatch(anyCollection(), eq(START_DATE), eq(END_DATE)))
-                .thenReturn(calendarDays);
+        when(calendarPeriodRepository.findForScheduleBatch(
+                anyCollection(),
+                any(),
+                eq(START_DATE),
+                eq(END_DATE)
+        )).thenReturn(calendarPeriods);
        when(ruleRepository.findByGroupIdsAndSemesterIds(anyCollection(), anyCollection()))
                .thenReturn(rules);
        when(dateAssignmentRepository.findForScheduleRange(START_DATE, END_DATE)).thenReturn(List.of());
@@ -74,7 +78,7 @@ class ScheduleGenerationQueryCountTest {

        AcademicDateService academicDateService = new AcademicDateService(
                semesterRepository,
-                calendarDayRepository,
+                calendarPeriodRepository,
                assignmentRepository,
                false
        );
@@ -103,7 +107,12 @@ class ScheduleGenerationQueryCountTest {

        verify(semesterRepository).findOverlappingForSchedule(START_DATE, END_DATE);
        verify(assignmentRepository).findForScheduleBatch(anyCollection(), anyCollection());
-        verify(calendarDayRepository).findForScheduleBatch(anyCollection(), eq(START_DATE), eq(END_DATE));
+        verify(calendarPeriodRepository).findForScheduleBatch(
+                anyCollection(),
+                any(),
+                eq(START_DATE),
+                eq(END_DATE)
+        );
        verify(ruleRepository).findByGroupIdsAndSemesterIds(anyCollection(), anyCollection());
        verify(dateAssignmentRepository).findForScheduleRange(START_DATE, END_DATE);
        verify(scopeRepository).findByApplyModeOrderByDisplayOrderAsc("WEEKDAY");
@@ -112,7 +121,7 @@ class ScheduleGenerationQueryCountTest {
        verify(semesterRepository, never())
                .findFirstByStartDateLessThanEqualAndEndDateGreaterThanEqual(any(), any());
        verify(assignmentRepository, never()).findForSchedule(any(), any());
-        verify(calendarDayRepository, never())
+        verify(calendarPeriodRepository, never())
                .findByCalendarIdAndCourseNumberAndDate(any(), any(), any());
        verify(ruleRepository, never()).findByGroupIdAndSemesterId(any(), any());
        verify(dateAssignmentRepository, never()).findByDate(any());
@@ -122,7 +131,7 @@ class ScheduleGenerationQueryCountTest {
        int repositoryCalls = Stream.of(
                        semesterRepository,
                        assignmentRepository,
-                        calendarDayRepository,
+                        calendarPeriodRepository,
                        ruleRepository,
                        dateAssignmentRepository,
                        scopeRepository,
@@ -209,19 +218,22 @@ class ScheduleGenerationQueryCountTest {
        return assignment;
    }

-    private AcademicCalendarDay calendarDay(AcademicCalendar calendar, LocalDate date) {
+    private AcademicCalendarPeriod calendarPeriod(AcademicCalendar calendar,
+                                                  LocalDate startDate,
+                                                  LocalDate endDate) {
        AcademicCalendarActivityType theory = new AcademicCalendarActivityType();
        theory.setId(30L);
        theory.setCode("Т");
        theory.setName("Теоретическое обучение");
        theory.setAllowSchedule(true);

-        AcademicCalendarDay day = new AcademicCalendarDay();
-        day.setAcademicCalendar(calendar);
-        day.setCourseNumber(1);
-        day.setDate(date);
-        day.setActivityType(theory);
-        return day;
+        AcademicCalendarPeriod period = new AcademicCalendarPeriod();
+        period.setAcademicCalendar(calendar);
+        period.setCourseNumber(1);
+        period.setStartDate(startDate);
+        period.setEndDate(endDate);
+        period.setActivityType(theory);
+        return period;
    }

    private ScheduleRule rule(int index, Semester semester, List<StudentGroup> groups) {
--- a/backend/src/test/java/com/magistr/app/service/ScheduleQualityServiceTest.java
+++ b/backend/src/test/java/com/magistr/app/service/ScheduleQualityServiceTest.java
@@ -0,0 +1,315 @@
+package com.magistr.app.service;
+
+import com.magistr.app.dto.RenderedLessonDto;
+import com.magistr.app.model.AcademicYear;
+import com.magistr.app.model.Classroom;
+import com.magistr.app.model.ScheduleParity;
+import com.magistr.app.model.ScheduleVersion;
+import com.magistr.app.model.ScheduleVersionStatus;
+import com.magistr.app.model.Semester;
+import com.magistr.app.model.SemesterType;
+import com.magistr.app.model.StudentGroup;
+import com.magistr.app.model.TimeSlot;
+import com.magistr.app.repository.ClassroomRepository;
+import com.magistr.app.repository.GroupRepository;
+import com.magistr.app.repository.SemesterRepository;
+import com.magistr.app.repository.ScheduleVersionRepository;
+import com.magistr.app.repository.SubgroupRepository;
+import com.magistr.app.repository.TeacherPreferenceRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.util.List;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+class ScheduleQualityServiceTest {
+
+    private ScheduleQueryService scheduleQueryService;
+    private SemesterRepository semesterRepository;
+    private GroupRepository groupRepository;
+    private SubgroupRepository subgroupRepository;
+    private ClassroomRepository classroomRepository;
+    private TeacherPreferenceRepository preferenceRepository;
+    private EffectiveTimeSlotService effectiveTimeSlotService;
+    private ScheduleOverrideService scheduleOverrideService;
+    private ScheduleQualityService service;
+
+    @BeforeEach
+    void setUp() {
+        scheduleQueryService = mock(ScheduleQueryService.class);
+        semesterRepository = mock(SemesterRepository.class);
+        groupRepository = mock(GroupRepository.class);
+        subgroupRepository = mock(SubgroupRepository.class);
+        classroomRepository = mock(ClassroomRepository.class);
+        preferenceRepository = mock(TeacherPreferenceRepository.class);
+        effectiveTimeSlotService = mock(EffectiveTimeSlotService.class);
+        scheduleOverrideService = mock(ScheduleOverrideService.class);
+        service = new ScheduleQualityService(
+                scheduleQueryService,
+                semesterRepository,
+                groupRepository,
+                subgroupRepository,
+                classroomRepository,
+                preferenceRepository,
+                effectiveTimeSlotService,
+                scheduleOverrideService
+        );
+    }
+
+    @Test
+    void analysisExplainsGroupGapAndCapacityShortage() {
+        Semester semester = semester();
+        StudentGroup group = group(1L, 30L);
+        Classroom room = classroom(1L, "А-101", 20);
+        LocalDate date = LocalDate.of(2026, 9, 7);
+        List<RenderedLessonDto> lessons = List.of(
+                lesson(11L, date, 1, 1L, room, group),
+                lesson(12L, date, 3, 3L, room, group)
+        );
+        stubContext(semester, group, List.of(room), lessons);
+
+        var result = service.analyze(semester.getId());
+
+        assertThat(result.lessonCount()).isEqualTo(2);
+        assertThat(result.score()).isLessThan(100);
+        assertThat(result.problems().stream()
+                .flatMap(problem -> problem.problemTypes().stream()))
+                .contains("GROUP_GAP", "TEACHER_GAP", "ROOM_CAPACITY_SHORTAGE");
+        assertThat(result.metrics())
+                .filteredOn(metric -> "GROUP_GAPS".equals(metric.code()))
+                .singleElement()
+                .satisfies(metric -> assertThat(metric.value()).isEqualTo(1.0));
+    }
+
+    @Test
+    void analysisAggregatesRecurringProblemsByRuleAndSumsPenalty() {
+        Semester semester = semester();
+        StudentGroup group = group(1L, 30L);
+        Classroom room = classroom(1L, "А-101", 20);
+        LocalDate firstDate = LocalDate.of(2026, 9, 7);
+        List<RenderedLessonDto> lessons = List.of(
+                lesson(777L, 11L, firstDate, 1, 1L, room, group),
+                lesson(777L, 11L, firstDate.plusWeeks(1), 1, 1L, room, group)
+        );
+        stubContext(semester, group, List.of(room), lessons);
+
+        var result = service.analyze(semester.getId());
+
+        assertThat(result.totalProblemCount()).isOne();
+        assertThat(result.rawPenalty()).isEqualTo(18);
+        assertThat(result.problems())
+                .singleElement()
+                .satisfies(problem -> {
+                    assertThat(problem.scheduleRuleId()).isEqualTo(777L);
+                    assertThat(problem.affectedLessonCount()).isEqualTo(2);
+                    assertThat(problem.penalty()).isEqualTo(18);
+                    assertThat(problem.problemTypes()).containsExactly("ROOM_CAPACITY_SHORTAGE");
+                    assertThat(problem.issueLabels()).containsExactly("Аудитория меньше состава занятия");
+                });
+    }
+
+    @Test
+    void analysisMeasuresDailyDistributionSeparatelyFromOverload() {
+        Semester semester = semester();
+        StudentGroup group = group(1L, 20L);
+        Classroom room = classroom(1L, "А-101", 20);
+        LocalDate monday = LocalDate.of(2026, 9, 7);
+        LocalDate tuesday = monday.plusDays(1);
+        List<RenderedLessonDto> lessons = List.of(
+                lesson(11L, monday, 1, 1L, room, group),
+                lesson(12L, tuesday, 1, 1L, room, group),
+                lesson(13L, tuesday, 2, 2L, room, group),
+                lesson(14L, tuesday, 3, 3L, room, group)
+        );
+        stubContext(semester, group, List.of(room), lessons);
+
+        var result = service.analyze(semester.getId());
+
+        assertThat(result.metrics())
+                .filteredOn(metric -> "DISTRIBUTION_BALANCE".equals(metric.code()))
+                .singleElement()
+                .satisfies(metric -> {
+                    assertThat(metric.value()).isEqualTo(50.0);
+                    assertThat(metric.penalty()).isZero();
+                });
+    }
+
+    @Test
+    void recommendationsOfferOnlyValidatedTighterClassroom() {
+        Semester semester = semester();
+        StudentGroup group = group(1L, 20L);
+        Classroom oversized = classroom(1L, "Актовый зал", 120);
+        Classroom compact = classroom(2L, "А-204", 24);
+        LocalDate date = LocalDate.of(2026, 9, 7);
+        RenderedLessonDto source = lesson(11L, date, 1, 1L, oversized, group);
+        stubContext(semester, group, List.of(oversized, compact), List.of(source));
+        when(effectiveTimeSlotService.findEffective(date)).thenReturn(List.of(timeSlot(1L, 1)));
+
+        var result = service.recommendations(semester.getId(), 11L, date);
+
+        assertThat(result.candidates())
+                .filteredOn(candidate -> "REPLACE".equals(candidate.action()))
+                .singleElement()
+                .satisfies(candidate -> {
+                    assertThat(candidate.label()).contains("А-204", "24 мест");
+                    assertThat(candidate.penaltyDelta()).isPositive();
+                    assertThat(candidate.override().newClassroomId()).isEqualTo(2L);
+                });
+        verify(scheduleOverrideService).validateCandidate(any());
+    }
+
+    @Test
+    void draftQualityUsesItsOwnRulesInsteadOfPublishedSchedule() {
+        Semester semester = semester();
+        StudentGroup group = group(1L, 20L);
+        Classroom room = classroom(1L, "А-101", 20);
+        ScheduleVersion draft = new ScheduleVersion();
+        draft.setId(12L);
+        draft.setSemester(semester);
+        draft.setVersionNumber(2);
+        draft.setName("Черновик новой сетки");
+        draft.setStatus(ScheduleVersionStatus.DRAFT);
+        ScheduleVersionRepository versionRepository = mock(ScheduleVersionRepository.class);
+        ScheduleGeneratorService generatorService = mock(ScheduleGeneratorService.class);
+        service.setVersionDependencies(versionRepository, generatorService);
+        when(versionRepository.findByIdWithDetails(12L)).thenReturn(Optional.of(draft));
+        when(semesterRepository.findById(semester.getId())).thenReturn(Optional.of(semester));
+        when(generatorService.buildScheduleForVersion(12L, semester.getStartDate(), semester.getEndDate()))
+                .thenReturn(List.of(lesson(11L, LocalDate.of(2026, 9, 7), 1, 1L, room, group)));
+        when(groupRepository.findAll()).thenReturn(List.of(group));
+        when(subgroupRepository.findAllWithGroupsOrderByGroupNameAndName()).thenReturn(List.of());
+        when(classroomRepository.findAll()).thenReturn(List.of(room));
+        when(preferenceRepository.findApprovedForSemester(semester.getId())).thenReturn(List.of());
+
+        var result = service.analyze(semester.getId(), 12L);
+
+        assertThat(result.scheduleVersionStatus()).isEqualTo(ScheduleVersionStatus.DRAFT);
+        assertThat(result.scheduleVersionId()).isEqualTo(12L);
+        assertThat(result.lessonCount()).isOne();
+        verify(scheduleQueryService, never()).searchForAggregation(any(), any(), any(), any());
+    }
+
+    private void stubContext(
+            Semester semester,
+            StudentGroup group,
+            List<Classroom> classrooms,
+            List<RenderedLessonDto> lessons
+    ) {
+        when(semesterRepository.findById(semester.getId())).thenReturn(Optional.of(semester));
+        when(scheduleQueryService.searchForAggregation(
+                null,
+                null,
+                semester.getStartDate(),
+                semester.getEndDate()
+        )).thenReturn(lessons);
+        when(groupRepository.findAll()).thenReturn(List.of(group));
+        when(subgroupRepository.findAllWithGroupsOrderByGroupNameAndName()).thenReturn(List.of());
+        when(classroomRepository.findAll()).thenReturn(classrooms);
+        when(preferenceRepository.findApprovedForSemester(semester.getId())).thenReturn(List.of());
+    }
+
+    private Semester semester() {
+        AcademicYear academicYear = new AcademicYear();
+        academicYear.setId(1L);
+        academicYear.setTitle("2026/2027");
+        academicYear.setStartDate(LocalDate.of(2026, 9, 1));
+        academicYear.setEndDate(LocalDate.of(2027, 8, 31));
+        Semester semester = new Semester();
+        semester.setId(7L);
+        semester.setAcademicYear(academicYear);
+        semester.setSemesterType(SemesterType.autumn);
+        semester.setStartDate(LocalDate.of(2026, 9, 1));
+        semester.setEndDate(LocalDate.of(2026, 9, 30));
+        return semester;
+    }
+
+    private StudentGroup group(Long id, Long size) {
+        StudentGroup group = new StudentGroup();
+        group.setId(id);
+        group.setName("ИБ-101");
+        group.setGroupSize(size);
+        return group;
+    }
+
+    private Classroom classroom(Long id, String name, int capacity) {
+        Classroom classroom = new Classroom();
+        classroom.setId(id);
+        classroom.setName(name);
+        classroom.setCapacity(capacity);
+        classroom.setIsAvailable(true);
+        return classroom;
+    }
+
+    private TimeSlot timeSlot(Long id, int order) {
+        TimeSlot slot = new TimeSlot();
+        slot.setId(id);
+        slot.setOrderNumber(order);
+        slot.setStartTime(LocalTime.of(8 + order, 0));
+        slot.setEndTime(LocalTime.of(9 + order, 30));
+        return slot;
+    }
+
+    private RenderedLessonDto lesson(
+            Long ruleSlotId,
+            LocalDate date,
+            int order,
+            Long timeSlotId,
+            Classroom classroom,
+            StudentGroup group
+    ) {
+        return lesson(100L + ruleSlotId, ruleSlotId, date, order, timeSlotId, classroom, group);
+    }
+
+    private RenderedLessonDto lesson(
+            Long ruleId,
+            Long ruleSlotId,
+            LocalDate date,
+            int order,
+            Long timeSlotId,
+            Classroom classroom,
+            StudentGroup group
+    ) {
+        return new RenderedLessonDto(
+                ruleId,
+                ruleSlotId,
+                date,
+                date.getDayOfWeek().getValue(),
+                "Понедельник",
+                1,
+                ScheduleParity.BOTH,
+                timeSlotId,
+                order,
+                LocalTime.of(8 + order, 0),
+                LocalTime.of(9 + order, 30),
+                1L,
+                "Архитектура систем",
+                5L,
+                "Петров Пётр Петрович",
+                classroom.getId(),
+                classroom.getName(),
+                1L,
+                "Лекция",
+                "Очно",
+                null,
+                null,
+                List.of(),
+                List.of(),
+                List.of(group.getId()),
+                List.of(group.getName()),
+                "Т",
+                36,
+                0,
+                34,
+                ScheduleParity.BOTH
+        );
+    }
+}
--- a/backend/src/test/java/com/magistr/app/service/ScheduleQueryServiceTest.java
+++ b/backend/src/test/java/com/magistr/app/service/ScheduleQueryServiceTest.java
@@ -1,5 +1,7 @@
 package com.magistr.app.service;

+import com.magistr.app.dto.RenderedLessonDto;
+import com.magistr.app.model.TeacherDepartmentAssignment;
 import com.magistr.app.model.StudentGroup;
 import com.magistr.app.repository.GroupRepository;
 import com.magistr.app.repository.ScheduleOverrideRepository;
@@ -9,6 +11,8 @@ import org.junit.jupiter.params.provider.ValueSource;

 import java.time.LocalDate;
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
 import java.util.stream.IntStream;

 import static org.assertj.core.api.Assertions.assertThat;
@@ -138,6 +142,63 @@ class ScheduleQueryServiceTest {
        verify(overrideRepository).findByLessonDateBetweenWithDetails(startDate, endDate);
    }

+    @Test
+    void departmentSearchIncludesTeacherLessonsForGroupsFromAnotherDepartment() {
+        ScheduleGeneratorService generatorService = mock(ScheduleGeneratorService.class);
+        GroupRepository groupRepository = mock(GroupRepository.class);
+        ScheduleOverrideRepository overrideRepository = mock(ScheduleOverrideRepository.class);
+        StudentGroupLifecycleService groupLifecycleService = mock(StudentGroupLifecycleService.class);
+        TeacherDepartmentService teacherDepartmentService = mock(TeacherDepartmentService.class);
+        LocalDate startDate = LocalDate.of(2026, 5, 1);
+        LocalDate endDate = LocalDate.of(2026, 5, 7);
+        LocalDate lessonDate = LocalDate.of(2026, 5, 4);
+        StudentGroup externalGroup = group(20);
+        RenderedLessonDto ownTeacherLesson = mock(RenderedLessonDto.class);
+        RenderedLessonDto anotherDepartmentLesson = mock(RenderedLessonDto.class);
+        TeacherDepartmentAssignment ownAssignment = new TeacherDepartmentAssignment();
+        TeacherDepartmentAssignment anotherAssignment = new TeacherDepartmentAssignment();
+
+        when(ownTeacherLesson.teacherId()).thenReturn(10L);
+        when(ownTeacherLesson.date()).thenReturn(lessonDate);
+        when(anotherDepartmentLesson.teacherId()).thenReturn(11L);
+        when(anotherDepartmentLesson.date()).thenReturn(lessonDate);
+        when(groupRepository.findAll()).thenReturn(List.of(externalGroup));
+        when(groupLifecycleService.mayHaveScheduleInRange(externalGroup, startDate, endDate)).thenReturn(true);
+        when(generatorService.buildScheduleForGroups(any(), eq(startDate), eq(endDate)))
+                .thenReturn(List.of(ownTeacherLesson, anotherDepartmentLesson));
+        when(overrideRepository.findByLessonDateBetweenWithDetails(startDate, endDate)).thenReturn(List.of());
+        when(teacherDepartmentService.findAssignmentsForTeachersBetween(
+                Set.of(10L, 11L),
+                startDate,
+                endDate
+        )).thenReturn(Map.of(
+                10L, List.of(ownAssignment),
+                11L, List.of(anotherAssignment)
+        ));
+        when(teacherDepartmentService.hasDepartmentAssignmentAtDate(
+                List.of(ownAssignment), 7L, lessonDate
+        )).thenReturn(true);
+        when(teacherDepartmentService.hasDepartmentAssignmentAtDate(
+                List.of(anotherAssignment), 7L, lessonDate
+        )).thenReturn(false);
+        ScheduleQueryService service = new ScheduleQueryService(
+                generatorService,
+                groupRepository,
+                overrideRepository,
+                groupLifecycleService,
+                mock(AcademicDateService.class),
+                teacherDepartmentService
+        );
+
+        var result = service.searchForAggregation(7L, null, startDate, endDate);
+
+        assertThat(result).singleElement().satisfies(lesson ->
+                assertThat(lesson.teacherId()).isEqualTo(10L)
+        );
+        verify(groupRepository).findAll();
+        verify(groupRepository, never()).findByDepartmentId(7L);
+    }
+
    private StudentGroup group(int id) {
        StudentGroup group = new StudentGroup();
        group.setId((long) id);
--- a/backend/src/test/java/com/magistr/app/service/ScheduleRuleServiceConcurrencyIntegrationTest.java
+++ b/backend/src/test/java/com/magistr/app/service/ScheduleRuleServiceConcurrencyIntegrationTest.java
@@ -267,9 +267,15 @@ class ScheduleRuleServiceConcurrencyIntegrationTest {
                VALUES (?, 'autumn', DATE '2098-09-01', DATE '2099-01-31')
                RETURNING id
                """, Long.class, academicYearId);
+        Long scheduleVersionId = jdbcTemplate.queryForObject("""
+                INSERT INTO schedule_versions (semester_id, version_number, name, status)
+                VALUES (?, 1, 'Конкурентный черновик', 'DRAFT')
+                RETURNING id
+                """, Long.class, semesterId);

        return new SeedIds(
                semesterId,
+                scheduleVersionId,
                queryId("SELECT id FROM subjects WHERE name = 'Высшая математика'"),
                queryId("SELECT id FROM student_groups WHERE name = 'ИВТ-21-1'"),
                queryId("""
@@ -332,7 +338,8 @@ class ScheduleRuleServiceConcurrencyIntegrationTest {
                1,
                List.of(ids.groupId()),
                List.of(),
-                List.of(slot)
+                List.of(slot),
+                ids.scheduleVersionId()
        );
    }

@@ -355,6 +362,7 @@ class ScheduleRuleServiceConcurrencyIntegrationTest {

    private record SeedIds(
            long semesterId,
+            long scheduleVersionId,
            long subjectId,
            long groupId,
            long timeSlotId,
--- a/backend/src/test/java/com/magistr/app/service/ScheduleRuleServiceTest.java
+++ b/backend/src/test/java/com/magistr/app/service/ScheduleRuleServiceTest.java
@@ -10,6 +10,8 @@ import com.magistr.app.model.Role;
 import com.magistr.app.model.ScheduleParity;
 import com.magistr.app.model.ScheduleRule;
 import com.magistr.app.model.ScheduleRuleSlot;
+import com.magistr.app.model.ScheduleVersion;
+import com.magistr.app.model.ScheduleVersionStatus;
 import com.magistr.app.model.Semester;
 import com.magistr.app.model.SemesterType;
 import com.magistr.app.model.StudentGroup;
@@ -22,6 +24,8 @@ import com.magistr.app.repository.ClassroomRepository;
 import com.magistr.app.repository.GroupRepository;
 import com.magistr.app.repository.LessonTypesRepository;
 import com.magistr.app.repository.ScheduleRuleRepository;
+import com.magistr.app.repository.ScheduleRuleSlotRepository;
+import com.magistr.app.repository.ScheduleVersionRepository;
 import com.magistr.app.repository.SemesterRepository;
 import com.magistr.app.repository.SubjectRepository;
 import com.magistr.app.repository.SubgroupRepository;
@@ -88,6 +92,10 @@ class ScheduleRuleServiceTest {
    private SubgroupRepository subgroupRepository;
    @Mock
    private ScheduleGeneratorService scheduleGeneratorService;
+    @Mock
+    private ScheduleVersionRepository scheduleVersionRepository;
+    @Mock
+    private ScheduleRuleSlotRepository scheduleRuleSlotRepository;

    private ScheduleRuleService service;
    private Subject subject;
@@ -130,6 +138,8 @@ class ScheduleRuleServiceTest {
                subgroupRepository,
                scheduleGeneratorService
        );
+        service.setScheduleVersionRepository(scheduleVersionRepository);
+        service.setScheduleRuleSlotRepository(scheduleRuleSlotRepository);

        when(semesterRepository.findByIdForUpdate(SEMESTER_ID)).thenReturn(Optional.of(semester));
        when(semesterRepository.findAllByIdForUpdateOrderById(List.of(SEMESTER_ID)))
@@ -188,6 +198,76 @@ class ScheduleRuleServiceTest {
        assertThat(saved.practiceAcademicHours()).isZero();
    }

+    @Test
+    void allowsEditingPublishedVersionButRejectsArchive() {
+        ScheduleVersion published = scheduleVersion(90L, ScheduleVersionStatus.PUBLISHED);
+        when(scheduleVersionRepository.findByIdForUpdate(90L)).thenReturn(Optional.of(published));
+        when(scheduleRuleRepository.findActiveByVersionIdWithDetails(90L, null)).thenReturn(List.of());
+
+        ScheduleRuleDto saved = service.create(ruleRequestForVersion(90L, lectureSlot()));
+
+        assertThat(saved.scheduleVersionId()).isEqualTo(90L);
+        assertThat(saved.id()).isNotNull();
+
+        ScheduleVersion archived = scheduleVersion(91L, ScheduleVersionStatus.ARCHIVED);
+        when(scheduleVersionRepository.findByIdForUpdate(91L)).thenReturn(Optional.of(archived));
+
+        assertThatThrownBy(() -> service.create(ruleRequestForVersion(91L, lectureSlot())))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessage("Архивное расписание доступно только для просмотра; выберите опубликованное расписание или черновик");
+    }
+
+    @Test
+    void updatesRuleInsidePublishedVersionImmediately() {
+        ScheduleVersion published = scheduleVersion(90L, ScheduleVersionStatus.PUBLISHED);
+        ScheduleRule managed = persistedRule(RULE_ID, LifecycleEntity.STATUS_ACTIVE, "Очно");
+        managed.setScheduleVersion(published);
+        when(scheduleRuleRepository.findByIdForUpdate(RULE_ID)).thenReturn(Optional.of(managed));
+        when(scheduleVersionRepository.findByIdForUpdate(90L)).thenReturn(Optional.of(published));
+        when(scheduleRuleRepository.findActiveByVersionIdWithDetails(90L, RULE_ID)).thenReturn(List.of());
+
+        ScheduleRuleDto updated = service.update(
+                RULE_ID,
+                ruleRequestForVersion(90L, slot(
+                        RULE_ID * 10,
+                        ScheduleParity.BOTH,
+                        TEACHER_ID,
+                        CLASSROOM_ID,
+                        LECTURE_TYPE_ID,
+                        List.of(),
+                        "Онлайн"
+                ))
+        );
+
+        assertThat(updated.scheduleVersionId()).isEqualTo(90L);
+        assertThat(updated.slots()).singleElement()
+                .satisfies(slot -> {
+                    assertThat(slot.id()).isEqualTo(RULE_ID * 10);
+                    assertThat(slot.lessonFormat()).isEqualTo("Онлайн");
+                });
+        verify(scheduleGeneratorService).clearCache();
+    }
+
+    @Test
+    void rejectsRemovingPublishedSlotReferencedByOperationalHistory() {
+        ScheduleVersion published = scheduleVersion(90L, ScheduleVersionStatus.PUBLISHED);
+        ScheduleRule managed = persistedRule(RULE_ID, LifecycleEntity.STATUS_ACTIVE, "Очно");
+        managed.setScheduleVersion(published);
+        when(scheduleRuleRepository.findByIdForUpdate(RULE_ID)).thenReturn(Optional.of(managed));
+        when(scheduleVersionRepository.findByIdForUpdate(90L)).thenReturn(Optional.of(published));
+        when(scheduleRuleRepository.findActiveByVersionIdWithDetails(90L, RULE_ID)).thenReturn(List.of());
+        when(scheduleRuleSlotRepository.hasProtectedReferences(List.of(RULE_ID * 10))).thenReturn(true);
+
+        assertThatThrownBy(() -> service.update(
+                RULE_ID,
+                ruleRequestForVersion(90L, lectureSlot())
+        ))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessage("Нельзя удалить слот: на него ссылаются точечные изменения, заявки преподавателей или решения по отсутствиям");
+
+        verify(scheduleRuleRepository, never()).saveAndFlush(managed);
+    }
+
    @Test
    void rejectsActiveUserWithoutTeacherRole() {
        User administrator = user(TEACHER_ID, Role.ADMIN, "Администратор");
@@ -432,10 +512,42 @@ class ScheduleRuleServiceTest {
                1,
                List.of(GROUP_ID),
                null,
-                List.of(slots)
+                List.of(slots),
+                null
        );
    }

+    private ScheduleRuleDto ruleRequestForVersion(Long versionId, ScheduleRuleSlotDto... slots) {
+        return new ScheduleRuleDto(
+                null,
+                SUBJECT_ID,
+                null,
+                SEMESTER_ID,
+                null,
+                null,
+                2,
+                0,
+                0,
+                1,
+                1,
+                1,
+                List.of(GROUP_ID),
+                null,
+                List.of(slots),
+                versionId
+        );
+    }
+
+    private ScheduleVersion scheduleVersion(Long id, ScheduleVersionStatus status) {
+        ScheduleVersion version = new ScheduleVersion();
+        version.setId(id);
+        version.setSemester(semester);
+        version.setVersionNumber(1);
+        version.setName("Тестовая версия");
+        version.setStatus(status);
+        return version;
+    }
+
    private ScheduleRuleSlotDto lectureSlot() {
        return slot(
                ScheduleParity.BOTH, TEACHER_ID, CLASSROOM_ID,
@@ -460,8 +572,18 @@ class ScheduleRuleServiceTest {
                                     long lessonTypeId,
                                     List<Long> subgroupIds,
                                     String format) {
+        return slot(null, parity, teacherId, classroomId, lessonTypeId, subgroupIds, format);
+    }
+
+    private ScheduleRuleSlotDto slot(Long id,
+                                     ScheduleParity parity,
+                                     long teacherId,
+                                     long classroomId,
+                                     long lessonTypeId,
+                                     List<Long> subgroupIds,
+                                     String format) {
        return new ScheduleRuleSlotDto(
-                null,
+                id,
                1,
                null,
                parity,
--- a/backend/src/test/java/com/magistr/app/service/ScheduleVersionServiceTest.java
+++ b/backend/src/test/java/com/magistr/app/service/ScheduleVersionServiceTest.java
@@ -0,0 +1,163 @@
+package com.magistr.app.service;
+
+import com.magistr.app.dto.ScheduleVersionCreateDto;
+import com.magistr.app.model.AcademicYear;
+import com.magistr.app.model.ScheduleRule;
+import com.magistr.app.model.ScheduleRuleSlot;
+import com.magistr.app.model.ScheduleVersion;
+import com.magistr.app.model.ScheduleVersionHistory;
+import com.magistr.app.model.ScheduleVersionStatus;
+import com.magistr.app.model.Semester;
+import com.magistr.app.model.SemesterType;
+import com.magistr.app.model.Subject;
+import com.magistr.app.repository.ScheduleRuleRepository;
+import com.magistr.app.repository.ScheduleVersionHistoryRepository;
+import com.magistr.app.repository.ScheduleVersionRepository;
+import com.magistr.app.repository.SemesterRepository;
+import com.magistr.app.repository.UserRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+class ScheduleVersionServiceTest {
+
+    private ScheduleVersionRepository versionRepository;
+    private ScheduleVersionHistoryRepository historyRepository;
+    private ScheduleRuleRepository ruleRepository;
+    private SemesterRepository semesterRepository;
+    private ScheduleRuleService ruleService;
+    private ScheduleGeneratorService generatorService;
+    private ScheduleVersionService service;
+
+    @BeforeEach
+    void setUp() {
+        versionRepository = mock(ScheduleVersionRepository.class);
+        historyRepository = mock(ScheduleVersionHistoryRepository.class);
+        ruleRepository = mock(ScheduleRuleRepository.class);
+        semesterRepository = mock(SemesterRepository.class);
+        ruleService = mock(ScheduleRuleService.class);
+        generatorService = mock(ScheduleGeneratorService.class);
+        service = new ScheduleVersionService(
+                versionRepository,
+                historyRepository,
+                ruleRepository,
+                semesterRepository,
+                mock(UserRepository.class),
+                ruleService,
+                generatorService
+        );
+    }
+
+    @Test
+    void draftClonesRulesWithoutChangingPublishedVersion() {
+        Semester semester = semester();
+        ScheduleVersion published = version(1L, 1, ScheduleVersionStatus.PUBLISHED, semester);
+        ScheduleRule source = rule(21L, 100L, published);
+        when(semesterRepository.findByIdForUpdate(semester.getId())).thenReturn(Optional.of(semester));
+        when(versionRepository.findBySemesterIdForUpdate(semester.getId())).thenReturn(List.of(published));
+        when(versionRepository.saveAndFlush(any(ScheduleVersion.class))).thenAnswer(invocation -> {
+            ScheduleVersion draft = invocation.getArgument(0);
+            draft.setId(2L);
+            return draft;
+        });
+        when(ruleRepository.findActiveByVersionIdWithDetails(1L, null)).thenReturn(List.of(source));
+        when(ruleRepository.findActiveByVersionIdWithDetails(2L, null)).thenReturn(List.of());
+        when(versionRepository.findByIdWithDetails(2L)).thenAnswer(invocation -> Optional.of(
+                version(2L, 2, ScheduleVersionStatus.DRAFT, semester)
+        ));
+
+        service.createDraft(new ScheduleVersionCreateDto(semester.getId(), "Рабочая копия", 1L));
+
+        ArgumentCaptor<List<ScheduleRule>> copies = ArgumentCaptor.forClass(List.class);
+        verify(ruleRepository).saveAllAndFlush(copies.capture());
+        assertThat(copies.getValue()).singleElement().satisfies(copy -> {
+            assertThat(copy.getId()).isNull();
+            assertThat(copy.getVersionGroupId()).isEqualTo(100L);
+            assertThat(copy.getScheduleVersion().getId()).isEqualTo(2L);
+            assertThat(copy.getSubject()).isSameAs(source.getSubject());
+        });
+        assertThat(published.getStatus()).isEqualTo(ScheduleVersionStatus.PUBLISHED);
+    }
+
+    @Test
+    void publicationArchivesCurrentVersionAndActivatesWholeDraft() {
+        Semester semester = semester();
+        ScheduleVersion current = version(1L, 1, ScheduleVersionStatus.PUBLISHED, semester);
+        ScheduleVersion draft = version(2L, 2, ScheduleVersionStatus.DRAFT, semester);
+        ScheduleRule draftRule = rule(22L, 100L, draft);
+        when(versionRepository.findByIdForUpdate(2L)).thenReturn(Optional.of(draft));
+        when(versionRepository.findByIdWithDetails(2L)).thenReturn(Optional.of(draft));
+        when(versionRepository.findBySemesterIdForUpdate(semester.getId())).thenReturn(List.of(current, draft));
+        when(ruleRepository.findActiveByVersionIdWithDetails(2L, null)).thenReturn(List.of(draftRule));
+        when(ruleService.validateVersion(2L)).thenReturn(List.of());
+        when(versionRepository.saveAndFlush(any(ScheduleVersion.class))).thenAnswer(invocation -> invocation.getArgument(0));
+
+        service.publish(2L, "Утверждена новая сетка");
+
+        assertThat(current.getStatus()).isEqualTo(ScheduleVersionStatus.ARCHIVED);
+        assertThat(draft.getStatus()).isEqualTo(ScheduleVersionStatus.PUBLISHED);
+        assertThat(draft.getChangeReason()).isEqualTo("Утверждена новая сетка");
+        assertThat(draft.getPublishedAt()).isNotNull();
+        verify(generatorService).clearCache();
+        ArgumentCaptor<ScheduleVersionHistory> history = ArgumentCaptor.forClass(ScheduleVersionHistory.class);
+        verify(historyRepository, org.mockito.Mockito.times(2)).save(history.capture());
+        assertThat(history.getAllValues()).extracting(ScheduleVersionHistory::getAction)
+                .containsExactly("ARCHIVED", "PUBLISHED");
+    }
+
+    private Semester semester() {
+        AcademicYear year = new AcademicYear();
+        year.setId(5L);
+        year.setTitle("2026-2027");
+        Semester semester = new Semester();
+        semester.setId(7L);
+        semester.setAcademicYear(year);
+        semester.setSemesterType(SemesterType.autumn);
+        return semester;
+    }
+
+    private ScheduleVersion version(Long id,
+                                    int number,
+                                    ScheduleVersionStatus status,
+                                    Semester semester) {
+        ScheduleVersion version = new ScheduleVersion();
+        version.setId(id);
+        version.setSemester(semester);
+        version.setVersionNumber(number);
+        version.setName("Версия " + number);
+        version.setStatus(status);
+        return version;
+    }
+
+    private ScheduleRule rule(Long id, Long versionGroupId, ScheduleVersion version) {
+        Subject subject = new Subject();
+        subject.setId(11L);
+        subject.setName("Математика");
+        ScheduleRule rule = new ScheduleRule();
+        rule.setId(id);
+        rule.setSubject(subject);
+        rule.setSemester(version.getSemester());
+        rule.setScheduleVersion(version);
+        rule.setVersionGroupId(versionGroupId);
+        rule.setLectureAcademicHours(2);
+        rule.setLaboratoryAcademicHours(0);
+        rule.setPracticeAcademicHours(0);
+        rule.setLectureStartWeek(1);
+        rule.setLaboratoryStartWeek(1);
+        rule.setPracticeStartWeek(1);
+        ScheduleRuleSlot slot = new ScheduleRuleSlot();
+        slot.setScheduleRule(rule);
+        rule.setSlots(new LinkedHashSet<>(List.of(slot)));
+        return rule;
+    }
+}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
dipatrik10	ca0b9352f9	Merge branch 'Redesign' of https://gitea.zuev.company/Zuev/magistr into Redesign	2026-08-14 23:41:59 +03:00
dipatrik10	d384a43aa2	Поправил графики	2026-08-14 23:41:55 +03:00
Zuev	855d191517	.	2026-08-14 22:54:16 +03:00
Zuev	491e373cc3	исправил качество правил и изменение расписания (не черновика)	2026-08-12 01:07:35 +03:00
Zuev	18a97b293a	задачи 2 и 8	2026-08-11 18:18:08 +03:00
dipatrik10	519864b962	3 Задача	2026-08-11 01:55:02 +03:00
dipatrik10	5276729a69	1 Задача	2026-08-06 01:10:33 +03:00
Zuev	28268a38c0	р	2026-08-06 00:14:40 +03:00
dipatrik10	8f8ce0240b	Идеи	2026-08-05 23:31:48 +03:00
Zuev	840554c223	концепт AI ассистента	2026-08-05 15:37:34 +03:00
Zuev	cc422255a2	исправление хранения календаря	2026-07-31 21:24:11 +03:00
Zuev	87f3d98621	/	2026-07-30 03:18:43 +03:00