diff --git a/AGENTS.md b/AGENTS.md
index 5fbaaed..860095a 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -122,6 +122,20 @@ This document defines how AI agents should work with the WhatIDo codebase. Follo
 - **История версий**: `GET /api/lesson-reports/:id/versions`, восстановление — `POST /api/lesson-reports/:id/versions/:versionId/restore`, откат к тексту тьютора — `POST /api/lesson-reports/:id/ai/revert`. Хранится последние `LESSON_AI_VERSION_LIMIT` версий на отчёт
 - **Хуки фронтенда**: `openLessonVersions(id)` и `restoreLessonVersion(...)` живут в `public/admin.js` (модалка доступна с журнала, отчётов и дашборда), список и бейджи статусов — в `public/js/lessons.js`
 
+### 3e. Дата, время и часовой пояс (`server.js`, `public/js/datetime.js`)
+- **Настройки**: `timezone` (IANA, валидируется через `validTimezone`) и `time_format` (`'24h'` | `'12h'`). Сид — в `db/init.sql` + `db/migration.sql`. `DEFAULT_TIMEZONE` берётся из `process.env.TZ`, иначе `Europe/Moscow`
+- **Единая точка**: `public/js/datetime.js` подключается на **каждой** странице (`public/*.html`) перед `admin.js`/`js/*.js`, включая публичные `share.html`, `report.html`, `index.html`. Инициализация — `await initDateTime()` (грузят `timezone`/`time_format` из `GET /api/public-settings`). На админ-страницах вызов встроен в `checkAuth()` в `admin.js`
+- **Запрещено** в `public/`: прямые `toLocaleString`/`toLocaleDateString`/`toLocaleTimeString`, `new Date().getFullYear()` и `new Date().toISOString().slice(0,10)` для показа/вычисления дат. Только хелперы `datetime.js`
+- **Три семейства данных — не путать**:
+  - *instant* (`TIMESTAMPTZ`, ISO c `Z`) → `fmtFull` / `fmtDateTime` / `fmtDateFull` / `fmtDayMonth` / `fmtDateShort` / `fmtDateLong` / `fmtTimeOnly`. Зона применяется
+  - *чистая DATE-строка* `'YYYY-MM-DD'` (`lesson_date`, `taken_at`, `date_from`) → `fmtDateOnlyIso` / `fmtShortIso` / `fmtDayMonthIso` / `fmtDateOnlyLongIso`. **Без `Date()`** — иначе `new Date('YYYY-MM-DD')` (UTC-полночь) сдвинет дату на день назад
+  - *чистая TIME-строка* `'HH:MM(:SS)'` (`lesson_time`, `time_start`/`time_end`) → `fmtHmStr`. Учитывает 12h/24h, зону не применяет
+- **Текущие значения**: `todayIso()`, `nowHm()` (всегда 24h — для `<input type="time">`), `nowYear()`, `todayDow()`, `isoAddDays(iso, n)` (арифметика по ISO без зоны)
+- **Границы дней в SQL**: `TIMESTAMPTZ`-колонки фильтруются **только** через `tzDayStart`/`tzDayEnd` + `bindTz` (плейсхолдер `$TZ$` → `$N`, зона добавляется в `params` последней). Прямой `$n::date` по `created_at` считает дни в UTC (у контейнера `TimeZone=UTC`) и молча ломает границы — такого кода быть не должно. `DATE`-колонки (`lr.lesson_date`) сравниваются напрямую, зона не нужна
+- **`now()` по зоне**: `tzWall()` для «сейчас» и для `day_of_week`/расписания. Хардкод `'Europe/Moscow'` в SQL запрещён
+- **`bindTz` добавляет параметр только если в SQL есть `$TZ$`**: иначе Postgres отвечает `bind message supplies 1 parameters, but prepared statement requires 0`, а без global error handler запрос **висит вечно** (страница остаётся «Загрузка...»). Поэтому запрос с фильтрами дат работает, а без них — падает: проверяй оба варианта. Регрессия закрыта в `api.smoketest.js`
+- **`TZ` в compose** (`docker-compose.yml`, 5 мест) — только фолбэк для `DEFAULT_TIMEZONE`; фактическая зона берётся из настройки
+
 ### 4. API Patterns
 - **Middleware**: `requireAuth` — читает `X-Auth-Token`, 401 без валидной активной сессии. `requireAdmin` — самодостаточный (внутри вызывает `requireAuth`, если `req.user` ещё нет), 403 при `role !== 'admin'`. `optionalAuth` — для публичных страниц с персонализацией
 - **Филиалы**: `branchScope(user)` / `branchWhere(user, alias)` — для не-admin `user.branch_ids` (из `user_branches`) ограничивают выборку; у `admin` `ids = null` и фильтр не добавляется
@@ -310,6 +324,7 @@ guards against.
 | `Dockerfile` | App image build |
 | `public/*.html` | Frontend pages |
 | `public/admin.js` | Shared frontend logic, модалка отчёта о занятии (`openLessonModal`) |
+| `public/js/datetime.js` | Единая точка форматирования дат/времени: часовой пояс + 24h/12h. Подключается на всех страницах |
 | `public/lessons.html` | Отчёты о занятиях: список, фильтры, редактирование |
 | `scripts/backup.sh` | Host-level backup script (DB dump + storage export) |
 | `scripts/restore.sh` | Host-level restore script (DB dump + storage import) |
diff --git a/api.smoketest.js b/api.smoketest.js
index 0577b5a..2075878 100644
--- a/api.smoketest.js
+++ b/api.smoketest.js
@@ -123,6 +123,27 @@ async function main() {
   const restoredCheck = await api('/api/public-settings');
   ok('cache invalidation: restore visible', restoredCheck.data.system_name === before.data.system_name, restoredCheck.data.system_name);
 
+  const tzBad = await api('/api/settings', { token, method: 'PUT', body: { settings: { timezone: 'Nope/Nope' } } });
+  ok('timezone: невалидная зона отклонена', tzBad.status === 400, tzBad.status);
+  const fmtBad = await api('/api/settings', { token, method: 'PUT', body: { settings: { time_format: '36h' } } });
+  ok('time_format: невалидный формат отклонён', fmtBad.status === 400, fmtBad.status);
+  const pubTz = await api('/api/public-settings');
+  ok('public-settings отдаёт timezone/time_format', !!pubTz.data.timezone && ['24h', '12h'].includes(pubTz.data.time_format), {
+    timezone: pubTz.data.timezone,
+    time_format: pubTz.data.time_format,
+  });
+
+  const noFilter = await api('/api/files?limit=5', { token });
+  ok('files без фильтров: 200 (без висящих bind-параметров)', noFilter.status === 200, noFilter.status);
+  const withFilter = await api('/api/files?limit=5&date_from=2026-01-01&date_to=2026-12-31', { token });
+  ok('files с фильтром дат: 200', withFilter.status === 200, withFilter.status);
+  const entriesNoFilter = await api('/api/entries?limit=5', { token });
+  ok('entries без фильтров: 200', entriesNoFilter.status === 200, entriesNoFilter.status);
+  const entriesWithFilter = await api('/api/entries?limit=5&date_from=2026-01-01&date_to=2026-12-31', { token });
+  ok('entries с фильтром дат: 200', entriesWithFilter.status === 200, entriesWithFilter.status);
+  const photosFilter = await api('/api/photos?limit=5&date_from=2026-01-01&date_to=2026-12-31', { token });
+  ok('photos с фильтром дат: 200', photosFilter.status === 200, photosFilter.status);
+
   const groupCountBefore = Array.isArray(groups.data) ? groups.data.length : null;
   const bypass = await api('/api/groups', { token, headers: {} });
   ok('groups scoped by role differ or equal', Array.isArray(bypass.data));
diff --git a/db/init.sql b/db/init.sql
index 6e73438..7f2ef8a 100644
--- a/db/init.sql
+++ b/db/init.sql
@@ -131,6 +131,10 @@ INSERT INTO settings (key, value) VALUES ('camera_enabled', 'true')
 ON CONFLICT (key) DO NOTHING;
 INSERT INTO settings (key, value) VALUES ('trash_purge_days', '30')
 ON CONFLICT (key) DO NOTHING;
+INSERT INTO settings (key, value) VALUES ('timezone', 'Europe/Moscow')
+ON CONFLICT (key) DO NOTHING;
+INSERT INTO settings (key, value) VALUES ('time_format', '24h')
+ON CONFLICT (key) DO NOTHING;
 
 CREATE TABLE IF NOT EXISTS share_links (
   id SERIAL PRIMARY KEY,
diff --git a/db/migration.sql b/db/migration.sql
index 43ce1bd..644b313 100644
--- a/db/migration.sql
+++ b/db/migration.sql
@@ -429,3 +429,5 @@ WHERE key = 'lesson_ai_prompt' AND value IN (
 );
 
 INSERT INTO settings (key, value) VALUES ('notify_lesson_ai_formatted', 'false') ON CONFLICT (key) DO NOTHING;
+INSERT INTO settings (key, value) VALUES ('timezone', 'Europe/Moscow') ON CONFLICT (key) DO NOTHING;
+INSERT INTO settings (key, value) VALUES ('time_format', '24h') ON CONFLICT (key) DO NOTHING;
diff --git a/public/admin.js b/public/admin.js
index 141ea79..2fdca0f 100644
--- a/public/admin.js
+++ b/public/admin.js
@@ -18,6 +18,7 @@ async function checkAuth() {
     const res = await fetch(`${API}/api/auth/me`, { headers: hdr() });
     if (!res.ok) { cleanupSession(); return false; }
     currentUser = await res.json();
+    await initDateTime();
     return true;
   } catch { cleanupSession(); return false; }
 }
@@ -199,7 +200,7 @@ function notifyTime(ts) {
   if (diff < 60000) return 'только что';
   if (diff < 3600000) return `${Math.floor(diff / 60000)} мин назад`;
   if (diff < 86400000) return `${Math.floor(diff / 3600000)} ч назад`;
-  return d.toLocaleString('ru-RU', { day: '2-digit', month: '2-digit', hour: '2-digit', minute: '2-digit' });
+  return fmtDateTime(d);
 }
 
 function setNotifyUnread(n) {
@@ -490,13 +491,11 @@ let lessonModalGroups = null;
 let lessonModalGroupsPromise = null;
 
 function lessonTodayIso() {
-  const d = new Date();
-  return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
+  return todayIso();
 }
 
 function lessonNowTime() {
-  const d = new Date();
-  return `${String(d.getHours()).padStart(2, '0')}:${String(d.getMinutes()).padStart(2, '0')}`;
+  return nowHm();
 }
 
 async function loadLessonGroups() {
diff --git a/public/audit.html b/public/audit.html
index 1eae9e7..fbf9c66 100644
--- a/public/audit.html
+++ b/public/audit.html
@@ -54,6 +54,7 @@
 </div>
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/audit.js"></script>
 </body>
diff --git a/public/bans.html b/public/bans.html
index 55c394f..7c703e5 100644
--- a/public/bans.html
+++ b/public/bans.html
@@ -66,6 +66,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/bans.js"></script>
 <style>
diff --git a/public/branches.html b/public/branches.html
index 2289c79..8ba7c49 100644
--- a/public/branches.html
+++ b/public/branches.html
@@ -64,6 +64,7 @@
 </div>
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/branches.js"></script>
 <style>
diff --git a/public/dashboard.html b/public/dashboard.html
index 8b5993a..b2a1b1d 100644
--- a/public/dashboard.html
+++ b/public/dashboard.html
@@ -74,6 +74,7 @@
 </div>
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/dashboard.js"></script>
 </body>
diff --git a/public/error.html b/public/error.html
index db61364..b3d2ad8 100644
--- a/public/error.html
+++ b/public/error.html
@@ -37,6 +37,7 @@
 </div>
 </div>
 </div>
+<script src="/js/datetime.js"></script>
 <script src="/js/error.js"></script>
 </body>
 </html>
\ No newline at end of file
diff --git a/public/files.html b/public/files.html
index 69b3b2a..3bad45e 100644
--- a/public/files.html
+++ b/public/files.html
@@ -41,6 +41,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/files.js"></script>
 </body>
diff --git a/public/groups.html b/public/groups.html
index 7316216..957f58f 100644
--- a/public/groups.html
+++ b/public/groups.html
@@ -136,6 +136,7 @@
 </div>
 
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="vendor/jszip.min.js"></script>
 <script src="js/groups.js"></script>
diff --git a/public/index.html b/public/index.html
index a0ada8b..879ebca 100644
--- a/public/index.html
+++ b/public/index.html
@@ -184,6 +184,7 @@ nav a:hover{color:var(--text)}
 
 <div class="toast" id="toast">Готово!</div>
 
+<script src="js/datetime.js"></script>
 <script src="js/index.js"></script>
 </body>
 </html>
\ No newline at end of file
diff --git a/public/journal.html b/public/journal.html
index 3f9a6d6..018c062 100644
--- a/public/journal.html
+++ b/public/journal.html
@@ -265,6 +265,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/journal.js"></script>
 </body>
diff --git a/public/js/audit.js b/public/js/audit.js
index ec33388..189aa91 100644
--- a/public/js/audit.js
+++ b/public/js/audit.js
@@ -111,7 +111,8 @@ const FIELD_LABELS = {
 };
 
 function fmtTime(t) {
-  try { return new Date(t).toLocaleString('ru'); } catch { return t || ''; }
+  const f = fmtFull(t);
+  return f || t || '';
 }
 
 function parseTarget(t) {
diff --git a/public/js/bans.js b/public/js/bans.js
index b8e2b7e..05e6214 100644
--- a/public/js/bans.js
+++ b/public/js/bans.js
@@ -41,8 +41,8 @@ function renderPage() {
     <tr>
       <td><b>${esc(b.ip)}</b></td>
       <td><span class="reason-badge ${rcls}">${esc(reason)}</span></td>
-      <td>${new Date(b.created_at).toLocaleString('ru')}</td>
-      <td>${new Date(b.banned_until).toLocaleString('ru')}</td>
+      <td>${fmtFull(b.created_at)}</td>
+      <td>${fmtFull(b.banned_until)}</td>
       <td><button class="row-btn" data-unban="${esc(b.ip)}" title="Разблокировать">✕</button></td>
     </tr>`;
   }).join('');
diff --git a/public/js/dashboard.js b/public/js/dashboard.js
index df6e672..63e5b5d 100644
--- a/public/js/dashboard.js
+++ b/public/js/dashboard.js
@@ -30,22 +30,22 @@ function renderStats(s, disk) {
 
 function last14days() {
   const out = [];
-  for (let i = 13; i >= 0; i--) { const d = new Date(); d.setDate(d.getDate() - i); out.push(d); }
+  const base = todayIso();
+  for (let i = 13; i >= 0; i--) out.push(isoAddDays(base, -i));
   return out;
 }
 
 function renderActivity(activity) {
   const map = {};
   activity.forEach(a => { map[a.d] = a.n; });
-  const days = last14days().map(d => {
-    const iso = d.toISOString().slice(0, 10);
-    return { iso, label: d.toLocaleDateString('ru', { day: '2-digit', month: '2-digit' }), n: map[iso] || 0 };
+  const days = last14days().map(iso => {
+    return { iso, label: fmtDayMonthIso(iso), n: map[iso] || 0 };
   });
   const max = Math.max(1, ...days.map(x => x.n));
-  const todayIso = new Date().toISOString().slice(0, 10);
+  const todayKey = todayIso();
   document.getElementById('activityChart').innerHTML = days.map(x => `
     <div class="bar-col" title="${x.iso} — ${x.n} ${plural(x.n, 'запись', 'записи', 'записей')}">
-      <div class="bar ${x.iso === todayIso ? 'today' : ''}" style="height:${Math.round(x.n / max * 100)}%"></div>
+      <div class="bar ${x.iso === todayKey ? 'today' : ''}" style="height:${Math.round(x.n / max * 100)}%"></div>
       <div class="bar-day">${x.label}</div>
     </div>`).join('');
 }
@@ -60,7 +60,7 @@ function renderRecent(rows) {
         : `<div class="thumb"><i data-lucide="graduation-cap"></i></div>`}
       <div class="r-info">
         <div class="r-name">${esc(e.student_name)}</div>
-        <div class="r-meta">${esc(e.group_name)} · ${new Date(e.created_at).toLocaleString('ru', { day: '2-digit', month: '2-digit', hour: '2-digit', minute: '2-digit' })}</div>
+        <div class="r-meta">${esc(e.group_name)} · ${fmtDateTime(e.created_at)}</div>
       </div>
       <a class="r-link" href="journal.html" title="В журнал">→</a>
     </div>`).join('');
diff --git a/public/js/datetime.js b/public/js/datetime.js
new file mode 100644
index 0000000..7b476b1
--- /dev/null
+++ b/public/js/datetime.js
@@ -0,0 +1,136 @@
+const DateTime = { tz: '', hour12: false, ready: false, listeners: [] };
+
+const DT_FALLBACK_TZ = 'Europe/Moscow';
+const DT_CACHE = new Map();
+
+function dtValidTz(tz) {
+  if (!tz || typeof tz !== 'string') return false;
+  try { new Intl.DateTimeFormat('ru-RU', { timeZone: tz }); return true; } catch { return false; }
+}
+
+function dtBrowserTz() {
+  try { return Intl.DateTimeFormat().resolvedOptions().timeZone || DT_FALLBACK_TZ; } catch { return DT_FALLBACK_TZ; }
+}
+
+function dtFmt(opts) {
+  const key = DateTime.tz + '|' + (DateTime.hour12 ? '12' : '24') + '|' + JSON.stringify(opts);
+  let f = DT_CACHE.get(key);
+  if (!f) {
+    f = new Intl.DateTimeFormat('ru-RU', Object.assign({ timeZone: DateTime.tz, hour12: DateTime.hour12 }, opts));
+    DT_CACHE.set(key, f);
+  }
+  return f;
+}
+
+function dtDate(v) {
+  if (!v) return null;
+  const d = v instanceof Date ? v : new Date(v);
+  return Number.isNaN(d.getTime()) ? null : d;
+}
+
+function fmtDt(v, opts) {
+  const d = dtDate(v);
+  return d ? dtFmt(opts).format(d) : '';
+}
+
+function dtFmtParts() {
+  return { day: '2-digit', month: '2-digit', year: 'numeric', hour: '2-digit', minute: '2-digit', second: '2-digit' };
+}
+
+function fmtFull(v) { return fmtDt(v, dtFmtParts()); }
+function fmtDateTime(v) { return fmtDt(v, { day: '2-digit', month: '2-digit', hour: '2-digit', minute: '2-digit' }); }
+function fmtDateTimeY(v) { return fmtDt(v, { day: '2-digit', month: '2-digit', year: 'numeric', hour: '2-digit', minute: '2-digit' }); }
+function fmtDateFull(v) { return fmtDt(v, { day: '2-digit', month: '2-digit', year: 'numeric' }); }
+function fmtDayMonth(v) { return fmtDt(v, { day: '2-digit', month: '2-digit' }); }
+function fmtDateShort(v) { return fmtDt(v, { day: '2-digit', month: '2-digit', year: '2-digit' }); }
+function fmtDateLong(v) { return fmtDt(v, { day: 'numeric', month: 'long', year: 'numeric' }); }
+function fmtTimeOnly(v) { return fmtDt(v, { hour: '2-digit', minute: '2-digit' }); }
+
+function dtIsoMatch(v) {
+  const m = /^(\d{4})-(\d{2})-(\d{2})/.exec(String(v == null ? '' : v));
+  return m ? { y: m[1], m: m[2], d: m[3] } : null;
+}
+
+function dtPad(n) { return String(n).padStart(2, '0'); }
+
+function fmtDateOnlyIso(v) {
+  const p = dtIsoMatch(v);
+  return p ? `${p.d}.${p.m}.${p.y}` : '';
+}
+
+function fmtDayMonthIso(v) {
+  const p = dtIsoMatch(v);
+  return p ? `${p.d}.${p.m}` : '';
+}
+
+function fmtShortIso(v) {
+  const p = dtIsoMatch(v);
+  return p ? `${p.d}.${p.m}.${p.y.slice(2)}` : '';
+}
+
+function fmtHmStr(v) {
+  const m = /^(\d{1,2}):(\d{2})/.exec(String(v == null ? '' : v));
+  if (!m) return '';
+  const h = Number(m[1]);
+  const mm = m[2];
+  if (!DateTime.hour12) return `${dtPad(h)}:${mm}`;
+  const ap = h < 12 ? 'AM' : 'PM';
+  const h12 = h % 12 === 0 ? 12 : h % 12;
+  return `${h12}:${mm} ${ap}`;
+}
+
+function fmtDateOnlyLongIso(v) {
+  const p = dtIsoMatch(v);
+  if (!p) return '';
+  const months = ['января','февраля','марта','апреля','мая','июня','июля','августа','сентября','октября','ноября','декабря'];
+  return `${Number(p.d)} ${months[Number(p.m) - 1] || ''} ${p.y}`;
+}
+
+function dtZoneDate(d) {
+  try { return new Intl.DateTimeFormat('en-CA', { timeZone: DateTime.tz, year: 'numeric', month: '2-digit', day: '2-digit' }).format(d); } catch { return ''; }
+}
+
+function todayIso() { return dtZoneDate(new Date()); }
+
+function todayDow() {
+  const names = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'];
+  try { return names.indexOf(new Intl.DateTimeFormat('en-US', { timeZone: DateTime.tz, weekday: 'short' }).format(new Date())); } catch { return new Date().getDay(); }
+}
+
+function nowHm() {
+  try { return new Intl.DateTimeFormat('en-GB', { timeZone: DateTime.tz, hour: '2-digit', minute: '2-digit', hour12: false }).format(new Date()); } catch { return ''; }
+}
+
+function nowYear() {
+  try { return new Intl.DateTimeFormat('en-CA', { timeZone: DateTime.tz, year: 'numeric' }).format(new Date()); } catch { return String(new Date().getFullYear()); }
+}
+
+function isoAddDays(iso, n) {
+  const p = dtIsoMatch(iso);
+  if (!p) return '';
+  const d = new Date(Date.UTC(Number(p.y), Number(p.m) - 1, Number(p.d)));
+  d.setUTCDate(d.getUTCDate() + n);
+  return d.toISOString().slice(0, 10);
+}
+
+function dtApply(s) {
+  if (!s || typeof s !== 'object') return;
+  if (dtValidTz(s.timezone)) DateTime.tz = s.timezone;
+  DateTime.hour12 = s.time_format === '12h';
+  DateTime.listeners.forEach(fn => { try { fn(DateTime); } catch {} });
+}
+
+async function initDateTime() {
+  DateTime.tz = dtBrowserTz();
+  DateTime.hour12 = false;
+  try {
+    const res = await fetch('/api/public-settings');
+    if (res.ok) dtApply(await res.json());
+  } catch {}
+  DateTime.ready = true;
+  return DateTime;
+}
+
+function onDateTimeChange(fn) {
+  if (typeof fn === 'function') DateTime.listeners.push(fn);
+}
\ No newline at end of file
diff --git a/public/js/files.js b/public/js/files.js
index d2f1ba8..d494cc7 100644
--- a/public/js/files.js
+++ b/public/js/files.js
@@ -51,7 +51,7 @@ function fileCardHTML(f) {
       <div class="info">
         <div class="file-name"><a ${target}>${esc(f.name)}</a></div>
         ${meta}
-        <div class="time">${new Date(f.created_at).toLocaleString('ru')}${f.size ? ' · ' + humanSize(f.size) : ''}</div>
+        <div class="time">${fmtFull(f.created_at)}${f.size ? ' · ' + humanSize(f.size) : ''}</div>
       </div>
       <div class="f-actions">${action}</div>
     </div>
diff --git a/public/js/groups.js b/public/js/groups.js
index e45d23e..c392828 100644
--- a/public/js/groups.js
+++ b/public/js/groups.js
@@ -67,7 +67,7 @@ async function loadGroups() {
           <button class="btn-link" data-export-urls="${g.id}" data-group-name="${esc(g.name)}" title="Скачать .url файлы учеников группы">URL</button>
           <button class="btn-link" data-export-files="${g.id}" data-group-name="${esc(g.name)}" title="Скачать ZIP-архив файлов группы за период">ZIP</button>
         </div>
-        <div class="sched-status">${schedSet ? `${DAYS[g.day_of_week]} ${g.time_start.slice(0,5)}–${g.time_end.slice(0,5)}` : 'Не настроено'}</div>
+        <div class="sched-status">${schedSet ? `${DAYS[g.day_of_week]} ${fmtHmStr(g.time_start)}–${fmtHmStr(g.time_end)}` : 'Не настроено'}</div>
       </div>
     </div>`;
   }).join('') + `</div>`;
@@ -162,11 +162,11 @@ async function loadGroupPhotos() {
 
 function goPhotoPage(p) { photoPage = p; loadGroupPhotos(); }
 
-function fmtPhotoDate(d) { return d ? d.split('-').reverse().join('.') : ''; }
+function fmtPhotoDate(d) { return fmtDateOnlyIso(d); }
 
 function photoHTML(p) {
   const taken = p.taken_at ? `Дата: ${fmtPhotoDate(p.taken_at)}` : '';
-  const uploaded = `Загружено: ${new Date(p.created_at).toLocaleDateString('ru')}`;
+  const uploaded = `Загружено: ${fmtDateFull(p.created_at)}`;
   const isCover = currentCover && p.photo_path === currentCover;
   return `
     <div class="photo-item" data-photo-id="${p.id}" data-photo-path="${esc(p.photo_path)}" draggable="true">
@@ -274,7 +274,7 @@ async function exportGroup(id, name) {
       e.student_name,
       e.group_name,
       e.description.replace(/\n/g, ' '),
-      new Date(e.created_at).toLocaleString('ru'),
+      fmtFull(e.created_at),
       `${location.origin}/?nameInput=${encodeURIComponent(e.student_name)}`
     ]);
   });
@@ -318,8 +318,7 @@ function closeGroupFilesModal() {
 }
 
 function todayISOLocal() {
-  const d = new Date();
-  return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
+  return todayIso();
 }
 
 const GROUP_FILES_PHOTO_BOXES = ['groupFilesMainPhoto', 'groupFilesGallery', 'groupFilesOriginals'];
diff --git a/public/js/index.js b/public/js/index.js
index 4f62e1a..d776589 100644
--- a/public/js/index.js
+++ b/public/js/index.js
@@ -166,7 +166,7 @@ function pasteFileName(file) {
   if (base && !/^(image|photo|picture|blob|file|screenshot|снимок|скриншот|изображение|файл)$/i.test(stem)) return base;
   const d = new Date();
   const pad = n => String(n).padStart(2, '0');
-  const stamp = `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())} ${pad(d.getHours())}-${pad(d.getMinutes())}-${pad(d.getSeconds())}`;
+  const stamp = `${todayIso()} ${nowHm().replace(':', '-')}-${pad(d.getSeconds())}`;
   return `Вставка ${stamp}${extFromFile(file)}`;
 }
 
@@ -281,6 +281,7 @@ async function resolveModuleId(name) {
 }
 
 (async () => {
+  await initDateTime();
   try {
     const list = await fetchModules('', 50);
     if (list.length) {
diff --git a/public/js/journal.js b/public/js/journal.js
index 57f394d..36ccd70 100644
--- a/public/js/journal.js
+++ b/public/js/journal.js
@@ -124,7 +124,7 @@ function gridEntryHTML(e) {
         <div class="group">${esc(e.group_name)}${e.module_name ? ' · ' + esc(e.module_name) : ''}</div>
         <div class="desc">${esc(e.description)}${aiBadge(e)}</div>
         ${filesHTML(e.files)}
-        <div class="time">${new Date(e.created_at).toLocaleString('ru')}</div>
+        <div class="time">${fmtFull(e.created_at)}</div>
       </div>
       <button class="edit" data-edit="${e.id}" title="Редактировать">✎</button>
       ${mp ? `<button class="edit" data-enhance="${e.id}" title="Улучшить фото">✦</button>` : ''}
@@ -148,7 +148,7 @@ function cardEntryHTML(e) {
         ${filesHTML(e.files)}
       </div>
       <div class="foot">
-        <span>${new Date(e.created_at).toLocaleString('ru')}</span>
+        <span>${fmtFull(e.created_at)}</span>
         <span>
           <button class="edit" data-edit="${e.id}" title="Редактировать">✎</button>
           ${mp ? `<button class="edit" data-enhance="${e.id}" title="Улучшить фото">✦</button>` : ''}
@@ -220,7 +220,7 @@ function setView(v) {
 }
 
 function setDefaultDates() {
-  const today = new Date().toISOString().slice(0, 10);
+  const today = todayIso();
   document.getElementById('dateFrom').value = today;
   document.getElementById('dateTo').value = today;
 }
@@ -895,7 +895,7 @@ async function loadPhotoHistory() {
         </div>
         <div style="flex:1;min-width:0">
           <div style="font-size:.85rem">${esc(PHOTO_JOB_ACTION_LABELS[r.action] || r.action)}
-            <span style="color:var(--muted);font-size:.75rem;margin-left:6px">${esc(PHOTO_JOB_STATUS_LABELS[r.status] || r.status)} · ${esc(new Date(time).toLocaleString('ru'))}</span>
+            <span style="color:var(--muted);font-size:.75rem;margin-left:6px">${esc(PHOTO_JOB_STATUS_LABELS[r.status] || r.status)} · ${esc(fmtFull(time))}</span>
           </div>
           ${err}
         </div>
@@ -1229,7 +1229,7 @@ function renderEditAiStatus(e) {
   el.style.display = 'block';
   const changed = e.description_ai && e.description_original && e.description_ai !== e.description_original;
   const parts = [AI_STATUS_LABELS[e.ai_status] || `ИИ: ${e.ai_status}`];
-  if (e.ai_checked_at) parts.push(new Date(e.ai_checked_at).toLocaleString('ru'));
+  if (e.ai_checked_at) parts.push(fmtFull(e.ai_checked_at));
   let html = `<span>${esc(parts.join(' · '))}</span>`;
   if (changed) html += ` <button type="button" id="aiRevertBtn" class="ai-btn" style="font-size:.75rem" title="Вернуть исходный текст (до ИИ)">↩ Оригинал</button>`;
   html += ` <button type="button" id="aiRecheckBtn" class="ai-btn" style="font-size:.75rem" title="Проверить заново">⟳ Проверить</button>`;
@@ -1416,7 +1416,7 @@ async function exportCSV() {
       e.group_name,
       e.module_name || '',
       e.description.replace(/\n/g, ' '),
-      new Date(e.created_at).toLocaleString('ru'),
+      fmtFull(e.created_at),
       e.photo_path ? `${API}${e.photo_path}` : ''
     ]);
   });
diff --git a/public/js/lessons.js b/public/js/lessons.js
index ebd8dc2..823cf23 100644
--- a/public/js/lessons.js
+++ b/public/js/lessons.js
@@ -7,14 +7,12 @@ let groupsLoaded = false;
 function lessonDateText(iso) {
   const s = String(iso || '').slice(0, 10);
   if (!s) return '';
-  const d = new Date(s + 'T00:00:00');
-  if (Number.isNaN(d.getTime())) return s;
-  return d.toLocaleDateString('ru-RU', { day: '2-digit', month: '2-digit', year: '2-digit' });
+  return fmtShortIso(s) || s;
 }
 
 function lessonWhenText(r) {
   const date = lessonDateText(r.lesson_date);
-  const time = r.lesson_time ? String(r.lesson_time).slice(0, 5) : '';
+  const time = r.lesson_time ? fmtHmStr(r.lesson_time) : '';
   return time ? `${date}, ${time}` : date;
 }
 
diff --git a/public/js/links.js b/public/js/links.js
index 0bcdcc5..165f319 100644
--- a/public/js/links.js
+++ b/public/js/links.js
@@ -41,10 +41,10 @@ async function loadLinks() {
           ${l.group_name ? `Группа: <b>${esc(l.group_name)}</b>` : ''}
           ${l.student_name ? `${l.group_name ? ' · ' : ''}Ученик: <b>${esc(l.student_name)}</b>` : ''}
           ${l.date_from || l.date_to ? ` · период: <b>${l.date_from ? l.date_from.split('-').reverse().join('.') : '…'}</b> — <b>${l.date_to ? l.date_to.split('-').reverse().join('.') : '…'}</b>` : ' · весь период'}
-          ${expired ? ` · <span style="color:#ef4444;font-weight:600">срок действия истёк ${new Date(l.expires_at).toLocaleDateString('ru')}</span>` : l.expires_at ? ` · истекает ${new Date(l.expires_at).toLocaleDateString('ru')}` : ''}
+          ${expired ? ` · <span style="color:#ef4444;font-weight:600">срок действия истёк ${fmtDateFull(l.expires_at)}</span>` : l.expires_at ? ` · истекает ${fmtDateFull(l.expires_at)}` : ''}
           ${namesHidden ? ` · <span style="color:#f59e0b">имена скрыты</span>` : ''}
           ${l.access_password_hash ? ` · <span style="color:#2563eb">🔒 пароль</span>` : ''}
-          · создана ${new Date(l.created_at).toLocaleString('ru')}
+          · создана ${fmtFull(l.created_at)}
         </div>
       </div>
       <div style="display:flex;gap:8px;flex-shrink:0;align-items:center">
diff --git a/public/js/photos.js b/public/js/photos.js
index 30a78bc..ff358f9 100644
--- a/public/js/photos.js
+++ b/public/js/photos.js
@@ -36,7 +36,7 @@ function photoCardHTML(p) {
         <span class="ph-badge">${esc(p.source_label)}</span>
         <div class="ph-title">${esc(p.title || 'Без описания')}</div>
         ${meta.length ? `<div class="ph-meta">${meta.join(' · ')}</div>` : ''}
-        <div class="ph-time">${new Date(p.created_at).toLocaleString('ru')}</div>
+        <div class="ph-time">${fmtFull(p.created_at)}</div>
         ${link ? `<a class="ph-link" href="${link}">Открыть источник →</a>` : ''}
       </div>
     </div>
diff --git a/public/js/report.js b/public/js/report.js
index 88f1b85..2f4662f 100644
--- a/public/js/report.js
+++ b/public/js/report.js
@@ -24,9 +24,10 @@ function loadBrand(){
 function esc(s){return String(s==null?'':s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;').replace(/'/g,'&#039;')}
 function pad(n){return String(n).padStart(2,'0')}
 function toDate(v){if(!v)return null;const d=new Date(v);return isNaN(d.getTime())?null:d}
-function fmtDate(v){const d=toDate(v);return d?pad(d.getDate())+'.'+pad(d.getMonth()+1)+'.'+d.getFullYear():''}
-function fmtShort(v){const d=toDate(v);return d?pad(d.getDate())+'.'+pad(d.getMonth()+1)+'.'+String(d.getFullYear()).slice(2):''}
-function fmtLong(v){const d=toDate(v);return d?d.toLocaleDateString('ru-RU',{day:'numeric',month:'long',year:'numeric'}):''}
+function dtIsDateOnly(v){return typeof v==='string'&&/^\d{4}-\d{2}-\d{2}/.test(v)}
+function fmtDate(v){return dtIsDateOnly(v)?fmtDateOnlyIso(v):(v?fmtDateFull(v):'')}
+function fmtShort(v){return dtIsDateOnly(v)?fmtShortIso(v):(v?fmtDateShort(v):'')}
+function fmtLong(v){return dtIsDateOnly(v)?fmtDateOnlyLongIso(v):(v?fmtDateLong(v):'')}
 function plural(n,one,few,many){const m10=n%10,m100=n%100;if(m100>=11&&m100<=14)return many;if(m10===1)return one;if(m10>=2&&m10<=4)return few;return many}
 function words(n,one,few,many){return n+' '+plural(n,one,few,many)}
 function isImageFile(name){return /\.(jpe?g|jfif|png|gif|webp|bmp|avif|svg|ico)$/i.test(name||'')}
@@ -41,14 +42,19 @@ function hideEl(el,on){if(el)el.classList.toggle('rep-hidden',!!on)}
 function node(html){const t=document.createElement('template');t.innerHTML=html.trim();return t.content.firstElementChild}
 function periodLabel(from,to){
   if(!from&&!to)return '';
-  const a=toDate(from),b=toDate(to);
-  if(a&&b)return fmtDate(a)+' — '+fmtDate(b);
-  return fmtDate(a)||fmtDate(b);
+  if(from&&to)return fmtDate(from)+' — '+fmtDate(to);
+  return fmtDate(from)||fmtDate(to);
+}
+function dtIsoYear(v){
+  if(!v)return null;
+  if(dtIsDateOnly(v))return String(v).slice(0,4);
+  const d=toDate(v);
+  if(!d)return null;
+  try{return new Intl.DateTimeFormat('en-CA',{timeZone:DateTime.tz,year:'numeric'}).format(d).slice(0,4)}catch{return String(d.getFullYear())}
 }
 function yearLabel(from,to){
-  const a=toDate(from),b=toDate(to);
-  if(!a&&!b)return '';
-  const ay=a?a.getFullYear():null,by=b?b.getFullYear():null;
+  if(!from&&!to)return '';
+  const ay=dtIsoYear(from),by=dtIsoYear(to);
   if(ay&&by)return ay===by?String(ay):ay+' — '+String(by).slice(2);
   return String(ay||by);
 }
@@ -268,12 +274,15 @@ function statSep(variant){
   const extra=variant===1?' list__item--u-ip5wdmggw':(variant===2?' list__item--u-ixebr6v8q':'');
   return '<div class="list__item list__item--u-isd3lg3iz'+extra+'"></div>';
 }
+function dtYearMonth(d){
+  try{return new Intl.DateTimeFormat('en-CA',{timeZone:DateTime.tz,year:'numeric',month:'2-digit'}).format(d).slice(0,7)}catch{return d.getFullYear()+'-'+d.getMonth()}
+}
 function renderAbout(data,pool){
   const entries=data.entries||[];
   const photos=(data.photos||[]).length;
   const files=entries.reduce(function(n,e){return n+((e.files||[]).length)},0);
   const months={};
-  entries.forEach(function(e){const d=toDate(e.created_at);if(d)months[d.getFullYear()+'-'+d.getMonth()]=1});
+  entries.forEach(function(e){const d=toDate(e.created_at);if(d)months[dtYearMonth(d)]=1});
   const photosTotal=entries.filter(function(e){return e.photo_path}).length+photos;
   setText('aboutTitle',(data.name&&String(data.name).trim())||'Отчёт');
   setText('aboutLead',(data.message&&String(data.message).trim())||('Мы собрали '+words(entries.length,'запись','записи','записей')+' о работе за этот период — с фотографиями, файлами и описанием каждого занятия.'));
@@ -461,7 +470,7 @@ function renderFooter(data,heading,pool){
     const label=btn.querySelector('.text-block-wrap-div');
     if(label)label.textContent='Перейти по ссылке';
   }
-  setText('footCopy',state.systemName+' © '+new Date().getFullYear());
+  setText('footCopy',state.systemName+' © '+nowYear());
   setText('footBrand',heading);
   const fbox=document.getElementById('footerPhotoBox');
   const fimg=document.getElementById('footerPhoto');
@@ -563,5 +572,5 @@ function bindEvents(){
 
 bindEvents();
 makeNavLinks();
-loadBrand().then(function(){loadReport()});
+initDateTime().then(function(){return loadBrand()}).then(function(){loadReport()});
 function closeLightbox(){const lb=document.getElementById('lightbox');if(lb)lb.classList.remove('is-open')}
\ No newline at end of file
diff --git a/public/js/settings.js b/public/js/settings.js
index 93413cb..93b6cb8 100644
--- a/public/js/settings.js
+++ b/public/js/settings.js
@@ -1,6 +1,6 @@
-const DIRTY_FIELDS = ['systemName', 'spamInterval', 'footerLeft', 'footerRight', 'aiPrompt', 'aiAutoCheck', 'lessonAiPrompt', 'lessonAiEnabled', 'shareShowMessage', 'shareShowDate', 'shareShowNames', 'shareShowPhotos', 'cookieNoticeText', 'photoResolution', 'photoQuality', 'photoEngine', 'camEnabled', 'photoAiFaceMode', 'photoAiFaceModel', 'photoAiDevicePref', 'trashPurgeDays', 'notifyEnabled', 'notifyRetentionDays'];
+const DIRTY_FIELDS = ['systemName', 'timezone', 'timeFormat', 'spamInterval', 'footerLeft', 'footerRight', 'aiPrompt', 'aiAutoCheck', 'lessonAiPrompt', 'lessonAiEnabled', 'shareShowMessage', 'shareShowDate', 'shareShowNames', 'shareShowPhotos', 'cookieNoticeText', 'photoResolution', 'photoQuality', 'photoEngine', 'camEnabled', 'photoAiFaceMode', 'photoAiFaceModel', 'photoAiDevicePref', 'trashPurgeDays', 'notifyEnabled', 'notifyRetentionDays'];
 const NOTIFY_IDS = [];
-const SECTION_IDS = ['sec-system', 'sec-stack', 'sec-brand', 'sec-antispam', 'sec-share', 'sec-ai', 'sec-lesson-ai', 'sec-backup', 'sec-trash', 'sec-form', 'sec-notify', 'sec-photo', 'sec-photo-ai', 'sec-bans'];
+const SECTION_IDS = ['sec-system', 'sec-stack', 'sec-brand', 'sec-datetime', 'sec-antispam', 'sec-share', 'sec-ai', 'sec-lesson-ai', 'sec-backup', 'sec-trash', 'sec-form', 'sec-notify', 'sec-photo', 'sec-photo-ai', 'sec-bans'];
 const SPAM_MAX = 10080;
 const BAN_REASONS = {
   'honeypot': 'Антиспам-поле',
@@ -14,6 +14,67 @@ let logoOriginal = '';
 let currentSystemName = '';
 let photoAiService = null;
 
+function fillTimezoneOptions() {
+  const sel = document.getElementById('timezone');
+  if (!sel || sel.options.length) return;
+  let zones = [];
+  try { zones = Intl.supportedValuesOf('timeZone'); } catch { zones = []; }
+  if (!zones.length) zones = [DateTime.tz || 'Europe/Moscow'];
+  const browserTz = (() => { try { return Intl.DateTimeFormat().resolvedOptions().timeZone; } catch { return ''; } })();
+  const current = sel.dataset.value || DateTime.tz;
+  sel.innerHTML = zones.map(z => {
+    const off = tzOffsetLabel(z);
+    const label = off ? `${z} (UTC${off})` : z;
+    return `<option value="${esc(z)}">${esc(label)}</option>`;
+  }).join('');
+  const extra = browserTz && !zones.includes(browserTz) ? [browserTz] : [];
+  extra.forEach(z => { sel.insertAdjacentHTML('afterbegin', `<option value="${esc(z)}">${esc(z)}</option>`); });
+  if (current) sel.value = current;
+}
+
+function tzOffsetLabel(tz) {
+  try {
+    const parts = new Intl.DateTimeFormat('ru-RU', { timeZone: tz, timeZoneName: 'longOffset' }).formatToParts(new Date());
+    const name = parts.find(p => p.type === 'timeZoneName');
+    return name ? String(name.value).replace('GMT', '') : '';
+  } catch { return ''; }
+}
+
+function previewTz() {
+  const sel = document.getElementById('timezone');
+  return sel && dtValidTz(sel.value) ? sel.value : DateTime.tz;
+}
+
+function previewHour12() {
+  const el = document.getElementById('timeFormat');
+  return !!el && el.value === '12h';
+}
+
+function renderTimePreview() {
+  const box = document.getElementById('timePreview');
+  if (!box) return;
+  const tz = previewTz();
+  const h12 = previewHour12();
+  const now = new Date();
+  const sample = new Date(now.getTime() + 3661 * 1000);
+  box.innerHTML = `<span class="chip">Сейчас: ${esc(fmtIn(sample, tz, h12))}</span>`
+    + `<span class="chip-sub">${esc(fmtIn(now, tz, h12))}</span>`
+    + `<span class="chip-sub">Расписание 18:30 → ${esc(fmtHmIn('18:30:00', h12))}</span>`
+    + `<span class="chip-sub">Отчёт за занятие 09:05 → ${esc(fmtHmIn('09:05:00', h12))}</span>`;
+}
+
+function fmtIn(date, tz, h12) {
+  return new Intl.DateTimeFormat('ru-RU', { timeZone: tz, day: '2-digit', month: '2-digit', hour: '2-digit', minute: '2-digit', hour12: h12 }).format(date);
+}
+
+function fmtHmIn(v, h12) {
+  const saved = DateTime.hour12;
+  DateTime.hour12 = h12;
+  const out = fmtHmStr(v);
+  DateTime.hour12 = saved;
+  return out;
+}
+
 function renderLogoPreview() {
   const img = document.getElementById('logoPreviewImg');
   const fb = document.getElementById('logoPreviewFallback');
@@ -89,6 +150,15 @@ function humanizeMinutes(min) {
   return parts.join(' ');
 }
 
+function bindTimePreview() {
+  ['timezone', 'timeFormat'].forEach(id => {
+    const el = document.getElementById(id);
+    if (!el) return;
+    el.addEventListener('change', renderTimePreview);
+    el.addEventListener('input', renderTimePreview);
+  });
+}
+
 function updateDirty() {
   const dirtyCount = DIRTY_FIELDS.filter(id => {
     const el = document.getElementById(id);
@@ -123,6 +193,7 @@ function revertChanges() {
   renderLogoPreview();
   clearFieldError('spamInterval');
   updateSpamUi();
+  renderTimePreview();
   updateDirty();
   showToast('Изменения отменены');
 }
@@ -189,6 +260,7 @@ async function renderNotifyTypes(s) {
 }
 
 async function loadSettings() {
+  fillTimezoneOptions();
   const [sRes, stRes] = await Promise.all([
     fetch(`${API}/api/settings`, { headers: hdr() }),
     fetch(`${API}/api/stats`, { headers: hdr() }),
@@ -202,6 +274,11 @@ async function loadSettings() {
   renderLogoPreview();
   if (s.spam_interval_min !== undefined) document.getElementById('spamInterval').value = s.spam_interval_min;
   document.getElementById('trashPurgeDays').value = s.trash_purge_days !== undefined ? s.trash_purge_days : '30';
+  const tzSel = document.getElementById('timezone');
+  const storedTz = String(s.timezone || '');
+  tzSel.value = Array.from(tzSel.options).some(o => o.value === storedTz) ? storedTz : DateTime.tz;
+  document.getElementById('timeFormat').value = ['24h', '12h'].includes(s.time_format) ? s.time_format : '24h';
+  renderTimePreview();
   document.getElementById('footerLeft').value = s.footer_left || '';
   document.getElementById('footerRight').value = s.footer_right || '';
   document.getElementById('aiPrompt').value = s.ai_prompt || '';
@@ -272,7 +349,7 @@ async function loadSystemInfo(btn) {
       const data = await res.json();
       renderSystemInfo(data);
       renderStackInfo(data.stack);
-      const stamp = 'обновлено ' + new Date().toLocaleTimeString('ru', { hour: '2-digit', minute: '2-digit' });
+      const stamp = 'обновлено ' + fmtTimeOnly(new Date());
       const live = document.getElementById('systemLive');
       if (live) live.textContent = stamp;
       const stackLive = document.getElementById('stackLive');
@@ -804,6 +881,8 @@ async function saveSettings() {
       headers: hdrJson(),
       body: JSON.stringify({ settings: {
         system_name: document.getElementById('systemName').value.trim(),
+        timezone: document.getElementById('timezone').value,
+        time_format: document.getElementById('timeFormat').value,
         spam_interval_min: String(Math.round(Number(v))),
         footer_left: document.getElementById('footerLeft').value.trim(),
         footer_right: document.getElementById('footerRight').value.trim(),
@@ -828,6 +907,8 @@ async function saveSettings() {
       } })
     });
     if (res.ok) {
+      dtApply({ timezone: document.getElementById('timezone').value, time_format: document.getElementById('timeFormat').value });
+      renderTimePreview();
       showToast('Настройки сохранены');
       logoOriginal = currentLogo;
       snapshotDirty();
@@ -939,7 +1020,7 @@ async function loadBans() {
   el.innerHTML = bans.map(b => `
     <span class="chip ban-chip" data-chip="${esc(b.ip)}">
       <b>${esc(b.ip)}</b>
-      <span class="chip-sub">${esc(BAN_REASONS[b.reason] || b.reason || '—')} · до ${new Date(b.banned_until).toLocaleString('ru')}</span>
+      <span class="chip-sub">${esc(BAN_REASONS[b.reason] || b.reason || '—')} · до ${fmtFull(b.banned_until)}</span>
       <button type="button" class="unban-btn" data-unban="${esc(b.ip)}" title="Разблокировать" aria-label="Разблокировать ${esc(b.ip)}">✕</button>
     </span>`).join('');
 }
@@ -1091,6 +1172,7 @@ window.addEventListener('beforeunload', e => {
     try {
       await loadSettings();
       bindDirty();
+      bindTimePreview();
       if (authStatus) authStatus.classList.add('loaded');
     } catch {
       if (authStatus) { authStatus.classList.remove('loaded'); authStatus.classList.add('err'); authStatus.textContent = 'Ошибка загрузки настроек'; }
diff --git a/public/js/share.js b/public/js/share.js
index c7c4f18..1b05c54 100644
--- a/public/js/share.js
+++ b/public/js/share.js
@@ -240,13 +240,11 @@ function renderShare(data, password) {
   const showStudentMessage = !!data.show_student_message;
   const showEntryDate = !!data.show_entry_date;
   const dayKey = e => {
-    const d = new Date(e.created_at);
-    return `${d.getFullYear()}-${String(d.getMonth()+1).padStart(2,'0')}-${String(d.getDate()).padStart(2,'0')}`;
-  };
-  const dayLabel = k => {
-    const [y,m,d] = k.split('-').map(Number);
-    return new Date(y, m-1, d).toLocaleDateString('ru-RU', { day:'numeric', month:'long', year:'numeric' });
+    try {
+      return new Intl.DateTimeFormat('en-CA', { timeZone: DateTime.tz, year: 'numeric', month: '2-digit', day: '2-digit' }).format(new Date(e.created_at));
+    } catch { return ''; }
   };
+  const dayLabel = k => fmtDateOnlyLongIso(k);
   const cardHTML = e => {
     const body = [
       !isAnonymized ? `<div class="name">${esc(e.student_name)}</div>` : '',
@@ -262,7 +260,7 @@ function renderShare(data, password) {
           : `<div class="no-photo"><svg viewBox="0 0 240 160" preserveAspectRatio="xMidYMid meet" aria-hidden="true"><circle cx="105" cy="48" r="15"/><path d="M74 140 C74 106 88 92 105 92 C122 92 136 106 136 140 Z"/><circle cx="145" cy="58" r="18"/><path d="M108 144 C108 104 124 88 145 88 C166 88 182 104 182 144 Z"/></svg></div>`}
       </div>
       ${body ? `<div class="body">${body}</div>` : ''}
-      ${showEntryDate ? `<div class="foot">${new Date(e.created_at).toLocaleString('ru',{day:'2-digit',month:'2-digit',year:'numeric',hour:'2-digit',minute:'2-digit'})}</div>` : ''}
+      ${showEntryDate ? `<div class="foot">${fmtDateTimeY(e.created_at)}</div>` : ''}
     </div>
   `;
   };
@@ -288,6 +286,7 @@ document.addEventListener('click', e => {
 });
 
 (async()=>{
+  await initDateTime();
   await loadShare();
 })();
 
diff --git a/public/js/students.js b/public/js/students.js
index 3c7dacb..82a2c3a 100644
--- a/public/js/students.js
+++ b/public/js/students.js
@@ -226,7 +226,7 @@ async function exportStudentProfile(id) {
       return;
     }
     const blob = await res.blob();
-    downloadBlob(blob, `profile_${safeWindowsName(s.name)}_${new Date().toISOString().slice(0, 10)}.zip`);
+    downloadBlob(blob, `profile_${safeWindowsName(s.name)}_${todayIso()}.zip`);
     showToast(`Готово: ${s.name}`);
   } catch (err) {
     showToast('Ошибка при формировании профиля');
diff --git a/public/js/trash.js b/public/js/trash.js
index 4ea3e3d..e26751f 100644
--- a/public/js/trash.js
+++ b/public/js/trash.js
@@ -32,7 +32,7 @@ function entryHTML(e) {
         <div class="group">${esc(e.group_name)}</div>
         <div class="desc">${esc(e.description)}</div>
         ${filesHTML(e.files)}
-        <div class="trash-time">Удалена: ${new Date(e.deleted_at).toLocaleString('ru')}</div>
+        <div class="trash-time">Удалена: ${fmtFull(e.deleted_at)}</div>
       </div>
       <button class="restore-btn" data-restore="${e.id}" title="Восстановить">Восстановить</button>
       <button class="del-btn" data-hard="${e.id}" title="Пометить на удаление (через ${purgeDays} дней будет удалена безвозвратно)">&times;</button>
@@ -47,7 +47,7 @@ function groupHTML(g) {
       <div class="info">
         <div class="name">${esc(g.name)}</div>
         ${g.branch_name ? `<div class="group">${esc(g.branch_name)}</div>` : ''}
-        <div class="trash-time">Удалена: ${new Date(g.deleted_at).toLocaleString('ru')}</div>
+        <div class="trash-time">Удалена: ${fmtFull(g.deleted_at)}</div>
       </div>
       <button class="restore-btn" data-restore-group="${g.id}" title="Восстановить">Восстановить</button>
       <button class="del-btn" data-hard-group="${g.id}" title="Пометить на удаление (через ${purgeDays} дней будет удалена безвозвратно вместе с записями и фото)">&times;</button>
@@ -64,7 +64,7 @@ function pendingEntryHTML(e) {
         <div class="group">${esc(e.group_name)}</div>
         <div class="desc">${esc(e.description)}</div>
         ${filesHTML(e.files)}
-        <div class="trash-time warn">Удаление через ${purgeDays} дн.: ${new Date(e.purge_at).toLocaleString('ru')}</div>
+        <div class="trash-time warn">Удаление через ${purgeDays} дн.: ${fmtFull(e.purge_at)}</div>
       </div>
       <button class="restore-btn" data-unschedule="${e.id}" title="Вернуть в корзину">В корзину</button>
     </div>
@@ -78,7 +78,7 @@ function pendingGroupHTML(g) {
       <div class="info">
         <div class="name">${esc(g.name)}</div>
         ${g.branch_name ? `<div class="group">${esc(g.branch_name)}</div>` : ''}
-        <div class="trash-time warn">Удаление через ${purgeDays} дн.: ${new Date(g.purge_at).toLocaleString('ru')}</div>
+        <div class="trash-time warn">Удаление через ${purgeDays} дн.: ${fmtFull(g.purge_at)}</div>
       </div>
       <button class="restore-btn" data-unschedule-group="${g.id}" title="Вернуть в корзину">В корзину</button>
     </div>
diff --git a/public/js/worker.js b/public/js/worker.js
index 1faa8d2..0591f5f 100644
--- a/public/js/worker.js
+++ b/public/js/worker.js
@@ -70,7 +70,7 @@ function fmtDur(ms) {
 
 function fmtTime(t) {
   if (!t) return '—';
-  try { return new Date(t).toLocaleString('ru'); } catch { return String(t); }
+  return fmtFull(t) || String(t);
 }
 
 function ago(t) {
diff --git a/public/lessons.html b/public/lessons.html
index 5f55dc1..a747c3a 100644
--- a/public/lessons.html
+++ b/public/lessons.html
@@ -26,6 +26,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/lessons.js"></script>
 </body>
diff --git a/public/links.html b/public/links.html
index 0a77a75..a0bb4bb 100644
--- a/public/links.html
+++ b/public/links.html
@@ -91,6 +91,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/links.js"></script>
 </body>
diff --git a/public/modules.html b/public/modules.html
index 35e2ca1..7c0e9c3 100644
--- a/public/modules.html
+++ b/public/modules.html
@@ -83,6 +83,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/modules.js"></script>
 <style>
diff --git a/public/notifications.html b/public/notifications.html
index a7b991b..462bc6a 100644
--- a/public/notifications.html
+++ b/public/notifications.html
@@ -37,6 +37,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/notifications.js"></script>
 </body>
diff --git a/public/photos.html b/public/photos.html
index b7a6eb0..2ac1e93 100644
--- a/public/photos.html
+++ b/public/photos.html
@@ -43,6 +43,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/photos.js"></script>
 </body>
diff --git a/public/report.html b/public/report.html
index 6c045f4..3ec3d07 100644
--- a/public/report.html
+++ b/public/report.html
@@ -280,6 +280,7 @@
   </div>
 </div>
 
+<script src="/js/datetime.js"></script>
 <script src="/js/report.js"></script>
 </body>
 </html>
diff --git a/public/settings.html b/public/settings.html
index e92bee2..71ef7a6 100644
--- a/public/settings.html
+++ b/public/settings.html
@@ -22,6 +22,7 @@
         <a href="#sec-system" data-nav="sec-system" class="active"><i data-lucide="bar-chart-3"></i> Система</a>
         <a href="#sec-stack" data-nav="sec-stack"><i data-lucide="server"></i> Стек</a>
         <a href="#sec-brand" data-nav="sec-brand"><i data-lucide="palette"></i> Брендинг</a>
+        <a href="#sec-datetime" data-nav="sec-datetime"><i data-lucide="clock"></i> Дата и время</a>
         <a href="#sec-antispam" data-nav="sec-antispam"><i data-lucide="shield"></i> Антиспам</a>
         <a href="#sec-share" data-nav="sec-share"><i data-lucide="link"></i> Публичные ссылки</a>
         <a href="#sec-form" data-nav="sec-form"><i data-lucide="file-text"></i> Форма ответа</a>
@@ -91,6 +92,30 @@
         </div>
       </div>
 
+      <div class="settings-card" id="sec-datetime">
+        <div class="card-head">
+          <div class="ic"><i data-lucide="clock"></i></div>
+          <h3>Дата и время</h3>
+        </div>
+        <p class="hint">Часовой пояс, в котором показываются даты и время во всех разделах, и формат времени. На сервере дата в базе остаётся той же — меняется только отображение.</p>
+        <div class="settings-row">
+          <div class="settings-field">
+            <label for="timezone">Часовой пояс</label>
+            <select id="timezone" class="settings-input"></select>
+            <span class="hint">Определяет, какое время «сейчас» в расписании групп и границы дней в фильтрах</span>
+          </div>
+          <div class="settings-field">
+            <label for="timeFormat">Формат времени</label>
+            <select id="timeFormat" class="settings-input">
+              <option value="24h">24 часа (00:30)</option>
+              <option value="12h">12 часов AM/PM (12:30 PM)</option>
+            </select>
+            <span class="hint">Поля ввода времени остаются в формате 24 часов</span>
+          </div>
+        </div>
+        <div class="data-stats" id="timePreview"></div>
+      </div>
+
       <div class="settings-card" id="sec-antispam">
         <div class="card-head">
           <div class="ic"><i data-lucide="shield"></i></div>
@@ -412,6 +437,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/settings.js"></script>
 </body>
diff --git a/public/share.html b/public/share.html
index 98100be..d1c2760 100644
--- a/public/share.html
+++ b/public/share.html
@@ -124,6 +124,7 @@ body{font-family:'Segoe UI',system-ui,-apple-system,Roboto,sans-serif;background
   </div>
 </div>
 
+<script src="/js/datetime.js"></script>
 <script src="/js/share.js"></script>
 </body>
 </html>
\ No newline at end of file
diff --git a/public/students.html b/public/students.html
index 737c3b8..2f9c1e2 100644
--- a/public/students.html
+++ b/public/students.html
@@ -215,6 +215,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="vendor/jszip.min.js"></script>
 <script src="js/students.js"></script>
diff --git a/public/trash.html b/public/trash.html
index 2a84de1..ab15c33 100644
--- a/public/trash.html
+++ b/public/trash.html
@@ -46,6 +46,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/trash.js"></script>
 </body>
diff --git a/public/users.html b/public/users.html
index d5c028e..873956a 100644
--- a/public/users.html
+++ b/public/users.html
@@ -83,6 +83,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/users.js"></script>
 <style>
diff --git a/public/worker.html b/public/worker.html
index 42984a9..a83746c 100644
--- a/public/worker.html
+++ b/public/worker.html
@@ -187,6 +187,7 @@
 </div>
 <div class="toast" id="toast"></div>
 <script src="vendor/lucide.min.js"></script>
+<script src="js/datetime.js"></script>
 <script src="admin.js"></script>
 <script src="js/worker.js"></script>
 </body>
diff --git a/server.js b/server.js
index e3e2c64..16e8cde 100644
--- a/server.js
+++ b/server.js
@@ -1088,6 +1088,35 @@ async function trashPurgeDays() {
   return Number.isFinite(v) && v >= 1 && v <= 3650 ? v : 30;
 }
 
+const DEFAULT_TIMEZONE = (() => {
+  const fromEnv = String(process.env.TZ || '').trim();
+  return validTimezone(fromEnv) ? fromEnv : 'Europe/Moscow';
+})();
+
+function validTimezone(tz) {
+  if (!tz || typeof tz !== 'string') return false;
+  try { new Intl.DateTimeFormat('ru-RU', { timeZone: tz }); return true; } catch { return false; }
+}
+
+async function appTimezone() {
+  const v = String(await getSetting('timezone', DEFAULT_TIMEZONE) || '').trim();
+  return validTimezone(v) ? v : DEFAULT_TIMEZONE;
+}
+
+async function appHour12() {
+  return (await getSetting('time_format', '24h')) === '12h';
+}
+
+function tzDayStart(idx) { return `($${idx}::date::timestamp AT TIME ZONE $TZ$)`; }
+function tzDayEnd(idx) { return `($${idx}::date::timestamp + interval '1 day') AT TIME ZONE $TZ$`; }
+function tzWall() { return `(now() AT TIME ZONE $TZ$)`; }
+
+function bindTz(sql, params, tz) {
+  if (!sql.includes('$TZ$')) return { sql, params };
+  params.push(tz);
+  return { sql: sql.replace(/\$TZ\$/g, '$' + params.length), params };
+}
+
 async function purgeScheduledDeletions() {
   const erefs = await pool.query('SELECT id FROM entries WHERE purge_at IS NOT NULL AND purge_at <= now()');
   for (const r of erefs.rows) {
@@ -1780,8 +1809,8 @@ app.get('/api/settings', requireAdmin, async (_, res) => {
 
 app.get('/api/public-settings', apiLimiter, async (_, res) => {
   const out = await cacheWrap('public-settings', PUBLIC_TTL_MS, async () => {
-    const keys = ['system_name', 'system_logo', 'footer_left', 'footer_right', 'share_show_student_message', 'share_show_entry_date', 'share_show_student_names', 'share_show_group_photos', 'cookie_notice_text', 'spam_interval_min', 'photo_capture_resolution', 'photo_capture_quality', 'photo_enhance_engine', 'camera_enabled', 'photo_ai_face_mode', 'photo_ai_face_model', 'photo_ai_device_pref'];
-    const defaults = { system_name: 'WhatIDo', system_logo: '', spam_interval_min: '30', photo_capture_resolution: '640x480', photo_capture_quality: '0.92', photo_enhance_engine: 'auto', camera_enabled: 'true', photo_ai_face_mode: PHOTO_AI_DEFAULT_FACE_MODE, photo_ai_face_model: PHOTO_AI_FACE_MODEL, photo_ai_device_pref: 'auto' };
+    const keys = ['system_name', 'system_logo', 'footer_left', 'footer_right', 'share_show_student_message', 'share_show_entry_date', 'share_show_student_names', 'share_show_group_photos', 'cookie_notice_text', 'spam_interval_min', 'photo_capture_resolution', 'photo_capture_quality', 'photo_enhance_engine', 'camera_enabled', 'photo_ai_face_mode', 'photo_ai_face_model', 'photo_ai_device_pref', 'timezone', 'time_format'];
+    const defaults = { system_name: 'WhatIDo', system_logo: '', spam_interval_min: '30', photo_capture_resolution: '640x480', photo_capture_quality: '0.92', photo_enhance_engine: 'auto', camera_enabled: 'true', photo_ai_face_mode: PHOTO_AI_DEFAULT_FACE_MODE, photo_ai_face_model: PHOTO_AI_FACE_MODEL, photo_ai_device_pref: 'auto', timezone: DEFAULT_TIMEZONE, time_format: '24h' };
     const result = {};
     for (const k of keys) result[k] = await getSetting(k, defaults[k] || '');
     const rm = /^(\d{2,5})x(\d{2,5})$/.exec(result.photo_capture_resolution);
@@ -1859,6 +1888,12 @@ app.put('/api/settings', requireAdmin, async (req, res) => {
     if (key === 'lesson_ai_prompt' && String(value).length > 8000) {
       return res.status(400).json({ error: 'lesson_ai_prompt длиннее 8000 символов' });
     }
+    if (key === 'timezone' && !validTimezone(String(value).trim())) {
+      return res.status(400).json({ error: 'timezone должен быть корректным часовым поясом IANA, например Europe/Moscow' });
+    }
+    if (key === 'time_format' && !['24h', '12h'].includes(String(value))) {
+      return res.status(400).json({ error: 'time_format должен быть 24h или 12h' });
+    }
     if (key.startsWith('notify_') && key !== 'notify_retention_days' && !['true', 'false'].includes(String(value))) {
       return res.status(400).json({ error: `${key} должен быть true или false` });
     }
@@ -2771,10 +2806,10 @@ app.get('/api/share/:token', fileLimiter, async (req, res) => {
     const params = [];
     if (l.group_id) { params.push(l.group_id); conditions.push(`e.group_id = $${params.length}`); }
     if (l.student_name) { params.push(l.student_name); conditions.push(`e.student_name = $${params.length}`); }
-    if (l.date_from) { params.push(l.date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
-    if (l.date_to) { params.push(l.date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
+    if (l.date_from) { params.push(l.date_from); conditions.push(`e.created_at >= ${tzDayStart(params.length)}`); }
+    if (l.date_to) { params.push(l.date_to); conditions.push(`e.created_at < ${tzDayEnd(params.length)}`); }
     conditions.push('e.deleted_at IS NULL');
-    const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
+    const where = conditions.length ? ' WHERE ' + bindTz(conditions.join(' AND '), params, await appTimezone()).sql : '';
     const { rows: entries } = await pool.query(
       `SELECT e.*, g.name AS group_name FROM entries e
        JOIN groups g ON g.id = e.group_id${where} ORDER BY e.created_at DESC`,
@@ -2857,14 +2892,15 @@ app.get('/api/share/:shareToken/files/:fileToken', fileLimiter, async (req, res)
   const params = [];
   if (l.group_id) { params.push(l.group_id); conditions.push(`e.group_id = $${params.length}`); }
   if (l.student_name) { params.push(l.student_name); conditions.push(`e.student_name = $${params.length}`); }
-  if (l.date_from) { params.push(l.date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
-  if (l.date_to) { params.push(l.date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
+  if (l.date_from) { params.push(l.date_from); conditions.push(`e.created_at >= ${tzDayStart(params.length)}`); }
+  if (l.date_to) { params.push(l.date_to); conditions.push(`e.created_at < ${tzDayEnd(params.length)}`); }
   params.push(fileToken);
+  const bound = bindTz(conditions.join(' AND '), params, await appTimezone());
   const { rows } = await pool.query(
     `SELECT pf.path, pf.name FROM project_files pf
      JOIN entries e ON e.id = pf.entry_id
-     WHERE pf.token = $${params.length} AND ${conditions.join(' AND ')}`,
-    params
+     WHERE pf.token = $${params.length - 1} AND ${bound.sql}`,
+    bound.params
   );
   if (!rows.length) return res.status(404).json({ error: 'Not found' });
   const r = rows[0];
@@ -2920,10 +2956,10 @@ app.get('/api/groups/active', apiLimiter, async (_, res) => {
         AND day_of_week IS NOT NULL
         AND time_start IS NOT NULL
         AND time_end IS NOT NULL
-        AND day_of_week = EXTRACT(DOW FROM (now() AT TIME ZONE 'Europe/Moscow'))::int
-        AND (now() AT TIME ZONE 'Europe/Moscow')::time BETWEEN time_start AND time_end
+        AND day_of_week = EXTRACT(DOW FROM (now() AT TIME ZONE $1))::int
+        AND (now() AT TIME ZONE $1)::time BETWEEN time_start AND time_end
       ORDER BY id
-    `);
+    `, [await appTimezone()]);
     return rows;
   });
   res.json(rows);
@@ -4101,9 +4137,9 @@ app.put('/api/students/:id/photos/:pid/main', requireAuth, async (req, res) => {
   res.json({ ok: true, photo_path: rows[0].photo_path });
 });
 
-function fmtLongDate(iso) {
+function fmtLongDate(iso, tz) {
   if (!iso) return '';
-  return new Date(iso).toLocaleDateString('ru-RU', { day: 'numeric', month: 'long', year: 'numeric' });
+  return new Date(iso).toLocaleDateString('ru-RU', { day: 'numeric', month: 'long', year: 'numeric', timeZone: validTimezone(tz) ? tz : DEFAULT_TIMEZONE });
 }
 
 app.get('/api/export/student', requireAuth, async (req, res) => {
@@ -4141,18 +4177,18 @@ app.get('/api/export/student', requireAuth, async (req, res) => {
     const bw = branchWhere(req.user, 'g');
     if (dateFrom) {
       params.push(dateFrom);
-      conds.push(`e.created_at >= $${params.length}::date`);
+      conds.push(`e.created_at >= ${tzDayStart(params.length)}`);
     }
     if (dateTo) {
       params.push(dateTo);
-      conds.push(`e.created_at < ($${params.length}::date + interval '1 day')`);
+      conds.push(`e.created_at < ${tzDayEnd(params.length)}`);
     }
     if (bw.params.length) {
       const start = params.length + 1;
       conds.push(`g.branch_id IN (${bw.params.map((_, i) => '$' + (start + i)).join(',')})`);
       params.push(...bw.params);
     }
-    const condStr = conds.join(' AND ');
+    const condStr = bindTz(conds.join(' AND '), params, await appTimezone()).sql;
     const whereStr = ' WHERE ' + condStr;
     const [studRes, entriesRes, photosRes, mainsRes, filesRes, modulesRes, groupPhotosRes] = await Promise.all([
       pool.query(
@@ -4343,7 +4379,8 @@ app.get('/api/export/student', requireAuth, async (req, res) => {
 
     let period = null;
     if (hasPeriod) {
-      period = `Период: ${dateFrom ? fmtLongDate(dateFrom + 'T00:00:00') : 'начало'} — ${dateTo ? fmtLongDate(dateTo + 'T00:00:00') : 'сегодня'}`;
+      const exportTz = await appTimezone();
+      period = `Период: ${dateFrom ? fmtLongDate(dateFrom + 'T00:00:00', exportTz) : 'начало'} — ${dateTo ? fmtLongDate(dateTo + 'T00:00:00', exportTz) : 'сегодня'}`;
     }
 
     const reportData = {
@@ -4438,13 +4475,13 @@ app.get('/api/groups/:id/export/files', requireAuth, async (req, res) => {
     const params = [gid];
     if (dateFrom) {
       params.push(dateFrom);
-      conds.push(`e.created_at >= $${params.length}::date`);
+      conds.push(`e.created_at >= ${tzDayStart(params.length)}`);
     }
     if (dateTo) {
       params.push(dateTo);
-      conds.push(`e.created_at < ($${params.length}::date + interval '1 day')`);
+      conds.push(`e.created_at < ${tzDayEnd(params.length)}`);
     }
-    const condStr = conds.join(' AND ');
+    const condStr = bindTz(conds.join(' AND '), params, await appTimezone()).sql;
     const [studentsRes, filesRes, photosRes, entryPhotosRes, originalsRes] = await Promise.all([
       pool.query('SELECT id, name FROM students WHERE group_id = $1 ORDER BY name', [gid]),
       includeFiles
@@ -4602,8 +4639,8 @@ app.get('/api/entries', requireAuth, async (req, res) => {
   else conditions.push('e.deleted_at IS NULL');
   if (group_id) { params.push(group_id); conditions.push(`e.group_id = $${params.length}`); }
   if (module_id) { params.push(module_id); conditions.push(`e.module_id = $${params.length}`); }
-  if (date_from) { params.push(date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
-  if (date_to) { params.push(date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
+  if (date_from) { params.push(date_from); conditions.push(`e.created_at >= ${tzDayStart(params.length)}`); }
+  if (date_to) { params.push(date_to); conditions.push(`e.created_at < ${tzDayEnd(params.length)}`); }
   if (student_name) { params.push(student_name); conditions.push(`e.student_name = $${params.length}`); }
   if (search) { params.push(`%${search}%`); conditions.push(`(e.student_name ILIKE $${params.length} OR e.description ILIKE $${params.length})`); }
   if (req.user.role !== 'admin') {
@@ -4618,7 +4655,7 @@ app.get('/api/entries', requireAuth, async (req, res) => {
       conditions.push(`g.branch_id IN (${ph})`);
     }
   }
-  const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
+  const where = conditions.length ? ' WHERE ' + bindTz(conditions.join(' AND '), params, await appTimezone()).sql : '';
   const { rows: crows } = await pool.query(
     `SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id${where}`,
     params
@@ -4838,8 +4875,8 @@ app.get('/api/files', requireAuth, async (req, res) => {
   if (search) { params.push(`%${search}%`); conditions.push(`pf.name ILIKE $${params.length}`); }
   if (student_name) { params.push(student_name); conditions.push(`e.student_name = $${params.length}`); }
   if (group_id) { params.push(group_id); conditions.push(`e.group_id = $${params.length}`); }
-  if (date_from) { params.push(date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
-  if (date_to) { params.push(date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
+  if (date_from) { params.push(date_from); conditions.push(`e.created_at >= ${tzDayStart(params.length)}`); }
+  if (date_to) { params.push(date_to); conditions.push(`e.created_at < ${tzDayEnd(params.length)}`); }
   if (req.user.role !== 'admin') {
     if (group_id && !(await groupBelongsToBranches(req.user, group_id))) {
       return res.status(403).json({ error: 'Нет доступа к этой группе' });
@@ -4852,7 +4889,7 @@ app.get('/api/files', requireAuth, async (req, res) => {
       conditions.push(`g.branch_id IN (${ph})`);
     }
   }
-  const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
+  const where = conditions.length ? ' WHERE ' + bindTz(conditions.join(' AND '), params, await appTimezone()).sql : '';
   const { rows: crows } = await pool.query(
     `SELECT count(*)::int AS n FROM project_files pf JOIN entries e ON e.id = pf.entry_id JOIN groups g ON g.id = e.group_id${where}`,
     params
@@ -4975,8 +5012,8 @@ app.get('/api/photos', requireAuth, async (req, res) => {
   if (search) { params.push(`%${search}%`); conditions.push(`t.title ILIKE $${params.length}`); }
   if (student_name) { params.push(student_name); conditions.push(`t.student_name = $${params.length}`); }
   if (group_id) { params.push(group_id); conditions.push(`t.group_id = $${params.length}`); }
-  if (date_from) { params.push(date_from); conditions.push(`t.created_at >= $${params.length}::date`); }
-  if (date_to) { params.push(date_to); conditions.push(`t.created_at < ($${params.length}::date + interval '1 day')`); }
+  if (date_from) { params.push(date_from); conditions.push(`t.created_at >= ${tzDayStart(params.length)}`); }
+  if (date_to) { params.push(date_to); conditions.push(`t.created_at < ${tzDayEnd(params.length)}`); }
   if (req.user.role !== 'admin') {
     if (group_id && !(await groupBelongsToBranches(req.user, group_id))) {
       return res.status(403).json({ error: 'Нет доступа к этой группе' });
@@ -4989,7 +5026,7 @@ app.get('/api/photos', requireAuth, async (req, res) => {
       conditions.push(`t.branch_id IN (${ph})`);
     }
   }
-  const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
+  const where = conditions.length ? ' WHERE ' + bindTz(conditions.join(' AND '), params, await appTimezone()).sql : '';
   const from = `FROM (
       SELECT 'entry'::text AS source_type, 'Главное фото записи'::text AS source_label,
              e.photo_path AS path, e.id AS source_id, e.student_name, e.group_id,
@@ -5053,6 +5090,7 @@ app.get('/api/photos', requireAuth, async (req, res) => {
 
 app.get('/api/stats', requireAuth, async (req, res) => {
   const payload = await cacheWrap('stats:' + scopeKey(req.user), STATS_TTL_MS, async () => {
+    const tz = await appTimezone();
     const isAdmin = req.user.role === 'admin';
     const s = branchScope(req.user);
     let groupFilter;
@@ -5076,7 +5114,7 @@ app.get('/api/stats', requireAuth, async (req, res) => {
       pool.query(`SELECT count(*)::int AS n FROM groups g${gTrash('visible')}`, groupsParams),
       pool.query(`SELECT count(*)::int AS n FROM groups g${groupsWhere}`, groupsParams),
       pool.query(`SELECT count(DISTINCT e.student_name)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${groupFilter.where}`, groupFilter.params),
-      pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL AND e.created_at >= now()::date${groupFilter.where}`, groupFilter.params),
+      (() => { const p = groupFilter.params.slice(); p.push(tz); return pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL AND e.created_at >= ${tzWall()}::date${groupFilter.where}`.replace(/\$TZ\$/g, '$' + p.length), p); })(),
       pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.purge_at IS NOT NULL${groupFilter.where}`, groupFilter.params),
       pool.query(`SELECT count(*)::int AS n FROM groups g${gTrash('pending')}`, groupsParams),
     ]);
@@ -5197,6 +5235,7 @@ app.get('/api/system-info', requireAdmin, async (_, res) => {
 app.get('/api/dashboard', requireAuth, async (req, res) => {
   const payload = await cacheWrap('dashboard:' + scopeKey(req.user), STATS_TTL_MS, async () => {
   const DAYS = ['Вс', 'Пн', 'Вт', 'Ср', 'Чт', 'Пт', 'Сб'];
+  const tz = await appTimezone();
   const isAdmin = req.user.role === 'admin';
   const s = branchScope(req.user);
   const branchIds = isAdmin ? [] : s.ids;
@@ -5213,24 +5252,24 @@ app.get('/api/dashboard', requireAuth, async (req, res) => {
         pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NOT NULL${ew ? whereEntry : ''}`, ew ? whereGroupParams : []),
         pool.query(`SELECT count(*)::int AS n FROM groups g${isAdmin ? '' : (branchIds.length ? ` WHERE g.branch_id IN (${branchIds.map((_, i) => `$${i + 1}`).join(',')})` : ' WHERE 1 = 0')}`, isAdmin ? [] : branchIds),
         pool.query(`SELECT count(DISTINCT e.student_name)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${ew ? whereEntry : ''}`, ew ? whereGroupParams : []),
-        pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL AND e.created_at >= now()::date${ew ? whereEntry : ''}`, ew ? whereGroupParams : []),
+        (() => { const p = (ew ? whereGroupParams : []).slice(); p.push(tz); return pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL AND e.created_at >= ${tzWall()}::date${ew ? whereEntry : ''}`.replace(/\$TZ\$/g, '$' + p.length), p); })(),
       ]);
       return { entries: entries.rows[0].n, trash: trash.rows[0].n, groups: groups.rows[0].n, students: students.rows[0].n, today: today.rows[0].n };
     })(),
     pool.query(
-      `SELECT to_char(e.created_at, 'YYYY-MM-DD') AS d, count(*)::int AS n
+      `SELECT to_char(e.created_at AT TIME ZONE $TZ$, 'YYYY-MM-DD') AS d, count(*)::int AS n
        FROM entries e JOIN groups g ON g.id = e.group_id
-       WHERE e.deleted_at IS NULL AND e.created_at >= (now() - interval '13 days')::date${whereEntry}
-       GROUP BY 1 ORDER BY 1`,
-      whereEntry ? whereGroupParams : []
+       WHERE e.deleted_at IS NULL AND e.created_at >= (${tzWall()} - interval '13 days')::date${whereEntry}
+       GROUP BY 1 ORDER BY 1`.replace(/\$TZ\$/g, '$' + (whereEntry ? whereGroupParams.length : 0) + 1),
+      (whereEntry ? whereGroupParams : []).concat([tz])
     ),
     pool.query(
       `SELECT g.* FROM groups g
        WHERE g.day_of_week IS NOT NULL AND g.time_start IS NOT NULL AND g.time_end IS NOT NULL
-         AND g.day_of_week = EXTRACT(DOW FROM (now() AT TIME ZONE 'Europe/Moscow'))::int
-         AND (now() AT TIME ZONE 'Europe/Moscow')::time BETWEEN g.time_start AND g.time_end${whereGroup}
-       ORDER BY g.id`,
-      whereGroup ? whereGroupParams : []
+         AND g.day_of_week = EXTRACT(DOW FROM ${tzWall()})::int
+         AND ${tzWall()}::time BETWEEN g.time_start AND g.time_end${whereGroup}
+       ORDER BY g.id`.replace(/\$TZ\$/g, '$' + (whereGroup ? whereGroupParams.length : 0) + 1),
+      (whereGroup ? whereGroupParams : []).concat([tz])
     ),
     pool.query(
       `SELECT e.id, e.student_name, e.photo_path, e.created_at, g.name AS group_name