баг-фикс завершён

frontend/admin/js/views/academic-calendar.js

@@ -1,5 +1,5 @@
 import { api } from '../api.js';
-import { escapeHtml, showAlert, hideAlert } from '../utils.js';
+import { escapeHtml, formatLocalDate, showAlert, hideAlert } from '../utils.js';
 
 const DAY_OPTIONS = [
     { value: 1, label: 'Понедельник', shortLabel: 'Пн' },
@@ -1473,24 +1473,36 @@ export async function initAcademicCalendar() {
     }
 
     function previousIsoDate(value) {
-        const date = new Date(`${value}T00:00:00Z`);
-        date.setUTCDate(date.getUTCDate() - 1);
-        return date.toISOString().slice(0, 10);
+        const date = parseLocalIsoDate(value);
+        date.setDate(date.getDate() - 1);
+        return formatLocalDate(date);
     }
 
     function enumerateDates(startIso, endIso) {
         const result = [];
-        const current = new Date(`${startIso}T00:00:00Z`);
-        const end = new Date(`${endIso}T00:00:00Z`);
+        const current = parseLocalIsoDate(startIso);
+        const end = parseLocalIsoDate(endIso);
         while (current <= end) {
-            const iso = current.toISOString().slice(0, 10);
-            const jsDay = current.getUTCDay();
+            const iso = formatLocalDate(current);
+            const jsDay = current.getDay();
             result.push({ iso, dayOfWeek: jsDay === 0 ? 7 : jsDay });
-            current.setUTCDate(current.getUTCDate() + 1);
+            current.setDate(current.getDate() + 1);
         }
         return result;
     }
 
+    function parseLocalIsoDate(value) {
+        const [year, month, day] = String(value).split('-').map(Number);
+        const date = new Date(year, month - 1, day, 12);
+        if (!year || !month || !day || Number.isNaN(date.getTime())
+            || date.getFullYear() !== year
+            || date.getMonth() !== month - 1
+            || date.getDate() !== day) {
+            throw new TypeError('Ожидалась дата в формате ГГГГ-ММ-ДД');
+        }
+        return date;
+    }
+
     function groupBy(items, keyFn) {
         const grouped = new Map();
         items.forEach(item => {