diff --git a/App/teacher.html b/App/teacher.html
index adb33d9..65ac75e 100644
--- a/App/teacher.html
+++ b/App/teacher.html
@@ -2372,8 +2372,13 @@ async function ivOpenStudent(sid){
 // === ÜBERSICHT ===
 // Lehrer-Übersicht: Stat-Bar + aktive Aufgaben + Top-Performer + Aktivitäts-Sparkline + Modul-Cards.
 // Drei parallele API-Calls (matrix + activity-week + assignments) — alle existing.
-// === Schuljahr-Datumsfilter für die Modul-Sektion ===
+// === Schuljahr-Datumsfilter für die Modul-Sektion (global, persistent) ===
 var _modFilter = { from: null, to: null };
+try {
+  var _mfStored = JSON.parse(localStorage.getItem('ggs-mod-filter') || 'null');
+  if (_mfStored && _mfStored.from && _mfStored.to) { _modFilter.from = _mfStored.from; _modFilter.to = _mfStored.to; }
+} catch (e) {}
+function saveModFilter() { try { localStorage.setItem('ggs-mod-filter', JSON.stringify(_modFilter)); } catch (e) {} }
 function ggsTodayStr() {
   var d = new Date();
   return d.getFullYear() + '-' + String(d.getMonth()+1).padStart(2,'0') + '-' + String(d.getDate()).padStart(2,'0');
@@ -2482,10 +2487,7 @@ function renderModulesSection(modStats) {
   html += '</div></div>';
   return html;
 }
-async function applyModFilter() {
-  var f = document.getElementById('mf-from'), t = document.getElementById('mf-to');
-  if (f && f.value) _modFilter.from = f.value;
-  if (t && t.value) _modFilter.to = t.value;
+async function refreshModulesSection() {
   var host = document.getElementById('ov-modules'); if (!host) return;
   host.style.opacity = '.5';
   var ms = await api('results?class_id=' + currentClassId + '&view=mod_stats&from=' + _modFilter.from + '&to=' + _modFilter.to);
@@ -2493,11 +2495,32 @@ async function applyModFilter() {
   host.style.opacity = '';
   host.innerHTML = renderModulesSection(ms);
 }
+async function applyModFilter() {
+  var f = document.getElementById('mf-from'), t = document.getElementById('mf-to');
+  if (f && f.value) _modFilter.from = f.value;
+  if (t && t.value) _modFilter.to = t.value;
+  saveModFilter();
+  await refreshModulesSection();
+}
 function resetModFilter() {
   _modFilter.from = ggsSchoolYearStart();
   _modFilter.to = ggsTodayStr();
+  saveModFilter();
   applyModFilter();
 }
+// Vom Modul-Detail-Modal aus den globalen Zeitraum ändern
+function setModDate(which, val) {
+  if (!val) return;
+  _modFilter[which] = val; saveModFilter();
+  if (_modDetail && _modDetail.moduleId) openModuleDetail(_modDetail.moduleId);
+  refreshModulesSection();
+}
+function resetModDateModal() {
+  _modFilter.from = ggsSchoolYearStart();
+  _modFilter.to = ggsTodayStr(); saveModFilter();
+  if (_modDetail && _modDetail.moduleId) openModuleDetail(_modDetail.moduleId);
+  refreshModulesSection();
+}
 
 // Avatar-Bild oder Emoji, gegebene Pixelgröße
 function ivTodayAvatar(emoji, px) {
@@ -3683,9 +3706,13 @@ function renderModDetail() {
   var html = '<div style="display:flex;align-items:center;gap:.6rem;margin-bottom:.6rem">';
   html += '<span style="font-size:2rem">'+d.module.icon+'</span>';
   html += '<div><h3 style="margin:0">'+esc(d.module.name)+'</h3>';
-  function dmy(s){ if(!s) return ''; var p=s.split('-'); return p[2]+'.'+p[1]+'.'+p[0].slice(2); }
-  var zeit = (d.from && d.to) ? ' · <b style="color:#4a6a4e">'+dmy(d.from)+'–'+dmy(d.to)+'</b>' : '';
-  html += '<div style="font-size:.7rem;color:#8a8a8a">Klasse: '+d.classStats.totalPlays+' Durchgänge · '+totalH+'h Spielzeit · Ø '+(d.classStats.avgStars||'–')+'★ · '+d.classStats.studentsActive+'/'+d.classStats.studentsTotal+' aktiv'+zeit+'</div></div></div>';
+  html += '<div style="font-size:.7rem;color:#8a8a8a">Klasse: '+d.classStats.totalPlays+' Durchgänge · '+totalH+'h Spielzeit · Ø '+(d.classStats.avgStars||'–')+'★ · '+d.classStats.studentsActive+'/'+d.classStats.studentsTotal+' aktiv</div>';
+  var mfFrom = d.from || _modFilter.from || '', mfTo = d.to || _modFilter.to || '';
+  html += '<div style="display:inline-flex;align-items:center;gap:.35rem;font-size:.68rem;color:#6a6a6a;margin-top:.3rem">Zeitraum: '
+        + '<input type="date" value="'+mfFrom+'" onchange="setModDate(\'from\',this.value)" style="font:inherit;padding:.12rem .35rem;border:1px solid #ccc;border-radius:5px">'
+        + '– <input type="date" value="'+mfTo+'" onchange="setModDate(\'to\',this.value)" style="font:inherit;padding:.12rem .35rem;border:1px solid #ccc;border-radius:5px">'
+        + '<button class="btn-sm" style="padding:.12rem .5rem" onclick="resetModDateModal()" title="Auf Schuljahresbeginn zurücksetzen">↺</button></div>';
+  html += '</div></div>';
 
   var hl = d.highlights || [];
   var champs = d.champions || {};