fix: Month grid lines, scroll throttle, custom dark date/time picker

- Month view: Replaced day-strip+events-area with full-height column
  divs (.month-col) so borders extend the full row height and clicking
  anywhere in a day column (including below events) navigates to day view.
  Events overlay uses pointer-events:none (pass-through) while span bars
  and +N-more labels stay pointer-events:all.
- Scroll navigation: Changed wheel handler from 80ms debounce to 500ms
  leading-edge throttle — one navigation per trackpad gesture.
- Custom date/time picker (date-picker.js): Dark calendar grid with
  prev/next navigation, today/selected highlighting, and a CSS
  scroll-snap time scroller (hours 0-23, minutes 0-59) matching the
  app's primary color. Language-aware (month names, day headers via t()).
- Event modal datetime inputs replaced with hidden inputs + .dt-display
  click targets that open the custom picker. setDtValue() helper keeps
  hidden input and display label in sync.

frontend/css/app.css

@@ -469,8 +469,7 @@ a { color: var(--primary); text-decoration: none; }
   letter-spacing: .5px; color: var(--text-2);
 }
 .month-kw-cell {
-  position: absolute; left: 0; top: 0; bottom: 0;
+  position: absolute; left: 0; top: 0; bottom: 0; width: 38px;
-  width: 38px;
   display: flex; align-items: flex-start; justify-content: center;
   padding-top: 6px;
   font-size: 13px; color: var(--text-3); font-weight: 700;
@@ -478,32 +477,34 @@ a { color: var(--primary); text-decoration: none; }
   cursor: default; user-select: none; z-index: 1;
   background: var(--bg-app);
 }
-.month-cell {
+/* Full-height column divs — click target + border */
-  flex: 1;
+.month-col {
-  border-right: 1px solid var(--border);
+  flex: 1; border-right: 1px solid var(--border);
-  padding: 4px 4px 0;
+  cursor: pointer; transition: background var(--transition);
-  cursor: pointer;
+  padding: 4px 4px 0; min-width: 0;
-  transition: background var(--transition);
-  min-width: 0;
 }
-.month-cell:last-child { border-right: none; }
+.month-col:last-child { border-right: none; }
-.month-cell:hover { background: var(--bg-hover); }
+.month-col:hover { background: var(--bg-hover); }
-.month-cell.today { background: rgba(66,133,244,.08); }
+.month-col.today { background: rgba(66,133,244,.08); }
-.month-cell.other-month .cell-day { color: var(--text-3); }
+.month-col.other-month .cell-day { color: var(--text-3); }
 .cell-day {
   font-size: 12px; font-weight: 500; color: var(--text-2);
   width: 26px; height: 26px;
   display: flex; align-items: center; justify-content: center;
   border-radius: 50%; flex-shrink: 0;
 }
-.cell-day.today {
+.cell-day.today { background: var(--today-color); color: #fff; font-weight: 700; }
-  background: var(--today-color);
+/* Events overlay — pointer-events:none so clicks pass to columns */
-  color: #fff; font-weight: 700;
+.month-events-overlay {
+  position: absolute; top: 30px; left: 0; right: 0; bottom: 0;
+  pointer-events: none; overflow: hidden; z-index: 2;
 }
 .month-more {
   position: absolute;
   font-size: 11px; color: var(--text-2); padding: 0 4px;
   cursor: pointer; font-weight: 500;
+  pointer-events: all;
+  white-space: nowrap; overflow: hidden;
 }
 .month-more:hover { color: var(--primary); }
 
@@ -901,32 +902,24 @@ a { color: var(--primary); text-decoration: none; }
   display: flex; flex-direction: column; flex: 1; overflow: hidden;
 }
 .month-row {
-  display: flex; flex: 1; position: relative; min-height: 0;
+  display: flex; flex: 1; position: relative; min-height: 100px;
   border-bottom: 1px solid var(--border);
 }
 .month-row:last-child { border-bottom: none; }
+/* row-right: flex row containing 7 full-height column divs + events overlay */
 .month-row-right {
-  margin-left: 38px; display: flex; flex-direction: column; flex: 1; min-width: 0;
+  margin-left: 38px; display: flex; flex: 1; position: relative; min-width: 0;
-}
-.month-day-strip {
-  display: flex; flex-shrink: 0;
-}
-.month-events-area {
-  position: relative; flex: 1;
-  min-height: 72px; /* 3 lanes × 22px + 6px padding */
-  overflow: hidden;
 }
 .month-span-event {
   position: absolute;
   height: 18px; line-height: 18px;
-  border-radius: 3px;
+  border-radius: 3px; padding: 0 6px;
-  padding: 0 6px;
   font-size: 11px; font-weight: 500;
   white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
   cursor: pointer; color: #fff;
   transition: filter var(--transition);
   box-sizing: border-box;
-  z-index: 2;
+  pointer-events: all;
 }
 .month-span-event:hover { filter: brightness(1.15); }
 .month-span-event.past { opacity: .45; }
@@ -947,3 +940,118 @@ a { color: var(--primary); text-decoration: none; }
   .logo-text { display: none; }
   .view-title { font-size: 16px; }
 }
+
+/* ── Custom Date/Time Display Field ─────────────────────── */
+.dt-display {
+  display: flex; align-items: center; justify-content: space-between;
+  background: var(--bg-app);
+  border: 1px solid var(--border);
+  border-radius: var(--radius-sm);
+  padding: 10px 12px;
+  color: var(--text-1);
+  cursor: pointer;
+  transition: border-color var(--transition);
+  user-select: none;
+  min-height: 42px;
+}
+.dt-display:hover, .dt-display:focus { border-color: var(--primary); outline: none; }
+.dt-display-text { font-size: 14px; }
+.dt-display-icon { color: var(--text-3); flex-shrink: 0; margin-left: 6px; }
+
+/* ── Date/Time Picker Card ───────────────────────────────── */
+.dtp-overlay {
+  position: fixed; inset: 0; z-index: 700;
+}
+.dtp-card {
+  position: fixed; z-index: 701;
+  background: var(--bg-surface);
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  box-shadow: var(--shadow-lg);
+  padding: 16px;
+  width: 272px;
+  user-select: none;
+}
+/* Calendar header */
+.dtp-cal-header {
+  display: flex; align-items: center; justify-content: space-between;
+  margin-bottom: 10px;
+}
+.dtp-month-label {
+  font-size: 14px; font-weight: 600; color: var(--text-1);
+}
+.dtp-nav-btn {
+  background: none; border: none; cursor: pointer;
+  color: var(--text-2); font-size: 22px; line-height: 1;
+  padding: 2px 6px; border-radius: var(--radius-sm);
+  transition: background var(--transition), color var(--transition);
+}
+.dtp-nav-btn:hover { background: var(--bg-hover); color: var(--text-1); }
+/* Day-of-week headers */
+.dtp-grid {
+  display: grid; grid-template-columns: repeat(7, 1fr);
+  gap: 2px; margin-bottom: 4px;
+}
+.dtp-dow {
+  text-align: center; font-size: 11px; font-weight: 600;
+  color: var(--text-3); padding: 4px 0; text-transform: uppercase;
+}
+/* Day cells */
+.dtp-day {
+  display: flex; align-items: center; justify-content: center;
+  height: 34px; border-radius: 6px;
+  font-size: 13px; font-weight: 500; color: var(--text-1);
+  cursor: pointer; transition: background var(--transition);
+}
+.dtp-day:hover { background: var(--bg-hover); }
+.dtp-day.other { color: var(--text-3); }
+.dtp-day.other:hover { background: var(--bg-hover); }
+.dtp-day.today { color: var(--primary); font-weight: 700; }
+.dtp-day.selected {
+  background: var(--primary) !important;
+  color: #fff !important; font-weight: 700;
+}
+/* Time picker */
+.dtp-time-row {
+  display: flex; align-items: center; justify-content: center;
+  gap: 4px; margin: 12px 0 8px;
+  border-top: 1px solid var(--border-light);
+  padding-top: 12px;
+}
+.dtp-colon {
+  font-size: 22px; font-weight: 600; color: var(--text-2);
+  padding: 0 2px; line-height: 1;
+  align-self: center;
+}
+.dtp-tc-wrap {
+  position: relative; width: 64px;
+}
+.dtp-tc {
+  height: calc(3 * 40px);     /* 120px = 3 visible items */
+  overflow-y: scroll;
+  scroll-snap-type: y mandatory;
+  scrollbar-width: none;
+  padding: 40px 0;            /* top/bottom padding so first/last can center */
+  box-sizing: content-box;
+}
+.dtp-tc::-webkit-scrollbar { display: none; }
+.dtp-ti {
+  height: 40px; line-height: 40px;
+  text-align: center; font-size: 20px; font-weight: 500;
+  scroll-snap-align: center;
+  border-radius: 8px;
+  cursor: pointer;
+  color: var(--text-2);
+  transition: background .1s, color .1s;
+}
+.dtp-ti:hover { color: var(--text-1); }
+.dtp-ti.selected {
+  background: var(--primary);
+  color: #fff;
+}
+/* Actions */
+.dtp-actions {
+  display: flex; justify-content: flex-end; gap: 8px;
+  margin-top: 12px; padding-top: 10px;
+  border-top: 1px solid var(--border-light);
+}

frontend/index.html

@@ -202,21 +202,37 @@
       <div class="form-row" id="ev-time-row">
         <div class="form-group half">
           <label>Start</label>
-          <input type="datetime-local" id="ev-start" />
+          <input type="hidden" id="ev-start" />
+          <div class="dt-display" id="ev-start-display" tabindex="0" role="button">
+            <span class="dt-display-text">—</span>
+            <svg class="dt-display-icon" viewBox="0 0 24 24" fill="currentColor" width="16" height="16"><path d="M19 3h-1V1h-2v2H8V1H6v2H5c-1.1 0-2 .9-2 2v14a2 2 0 002 2h14a2 2 0 002-2V5c0-1.1-.9-2-2-2zm0 16H5V8h14v11zM7 10h5v5H7z"/></svg>
+          </div>
         </div>
         <div class="form-group half">
           <label>Ende</label>
-          <input type="datetime-local" id="ev-end" />
+          <input type="hidden" id="ev-end" />
+          <div class="dt-display" id="ev-end-display" tabindex="0" role="button">
+            <span class="dt-display-text">—</span>
+            <svg class="dt-display-icon" viewBox="0 0 24 24" fill="currentColor" width="16" height="16"><path d="M19 3h-1V1h-2v2H8V1H6v2H5c-1.1 0-2 .9-2 2v14a2 2 0 002 2h14a2 2 0 002-2V5c0-1.1-.9-2-2-2zm0 16H5V8h14v11zM7 10h5v5H7z"/></svg>
+          </div>
         </div>
       </div>
       <div class="form-row" id="ev-date-row" style="display:none">
         <div class="form-group half">
           <label>Start</label>
-          <input type="date" id="ev-start-date" />
+          <input type="hidden" id="ev-start-date" />
+          <div class="dt-display" id="ev-start-date-display" tabindex="0" role="button">
+            <span class="dt-display-text">—</span>
+            <svg class="dt-display-icon" viewBox="0 0 24 24" fill="currentColor" width="16" height="16"><path d="M19 3h-1V1h-2v2H8V1H6v2H5c-1.1 0-2 .9-2 2v14a2 2 0 002 2h14a2 2 0 002-2V5c0-1.1-.9-2-2-2zm0 16H5V8h14v11zM7 10h5v5H7z"/></svg>
+          </div>
         </div>
         <div class="form-group half">
           <label>Ende</label>
-          <input type="date" id="ev-end-date" />
+          <input type="hidden" id="ev-end-date" />
+          <div class="dt-display" id="ev-end-date-display" tabindex="0" role="button">
+            <span class="dt-display-text">—</span>
+            <svg class="dt-display-icon" viewBox="0 0 24 24" fill="currentColor" width="16" height="16"><path d="M19 3h-1V1h-2v2H8V1H6v2H5c-1.1 0-2 .9-2 2v14a2 2 0 002 2h14a2 2 0 002-2V5c0-1.1-.9-2-2-2zm0 16H5V8h14v11zM7 10h5v5H7z"/></svg>
+          </div>
         </div>
       </div>
       <div class="form-group">

frontend/js/calendar.js

@@ -4,6 +4,7 @@ import { renderMonth }  from './views/month.js';
 import { renderWeek }   from './views/week.js';
 import { renderAgenda } from './views/agenda.js';
 import { openColorPicker } from './color-picker.js';
+import { openDatePicker, formatDtDisplay } from './date-picker.js';
 import { t, setLang, getLang } from './i18n.js';
 
 // Fetch avatar image as blob URL (with auth header)
@@ -540,12 +541,13 @@ function bindTopbar() {
   document.getElementById('btn-settings').onclick = openSettingsModal;
   document.getElementById('btn-create-event').onclick = () => openNewEventModal(new Date());
 
-  // Mouse wheel / trackpad scroll navigation
+  // Mouse wheel / trackpad scroll navigation (500ms cooldown = 1 nav per gesture)
-  let _wheelTimer = null;
+  let _wheelLast = 0;
   document.getElementById('view-container').addEventListener('wheel', e => {
     e.preventDefault();
-    if (_wheelTimer) return;
+    const now = Date.now();
-    _wheelTimer = setTimeout(() => { _wheelTimer = null; }, 80);
+    if (now - _wheelLast < 500) return;
+    _wheelLast = now;
     const dir = e.deltaY > 0 ? 1 : -1;
     if (state.currentView === 'agenda') return;
     if (state.currentView === 'month') {
@@ -710,6 +712,17 @@ function populateCalendarSelect(selectedId) {
   });
 }
 
+// ── Date field helpers ────────────────────────────────────
+function setDtValue(id, isoStr, mode) {
+  const input = document.getElementById(id);
+  if (input) input.value = isoStr || '';
+  const display = document.getElementById(id + '-display');
+  if (display) {
+    display.querySelector('.dt-display-text').textContent =
+      formatDtDisplay(isoStr, mode, getLang());
+  }
+}
+
 function openNewEventModal(date) {
   state.editingEvent = null;
   state.selectedEventColor = '';
@@ -723,10 +736,10 @@ function openNewEventModal(date) {
   const start = new Date(date);
   const end   = new Date(date);
   end.setHours(end.getHours() + 1);
-  document.getElementById('ev-start').value = toLocalDatetimeInput(start);
+  setDtValue('ev-start',      toLocalDatetimeInput(start), 'datetime');
-  document.getElementById('ev-end').value   = toLocalDatetimeInput(end);
+  setDtValue('ev-end',        toLocalDatetimeInput(end),   'datetime');
-  document.getElementById('ev-start-date').value = toDateInput(start);
+  setDtValue('ev-start-date', toDateInput(start),          'date');
-  document.getElementById('ev-end-date').value   = toDateInput(start);
+  setDtValue('ev-end-date',   toDateInput(start),          'date');
 
   toggleAlldayFields(false);
   populateCalendarSelect(null);
@@ -746,14 +759,14 @@ function openEditEventModal(ev) {
   document.getElementById('ev-allday').checked    = ev.allDay;
 
   if (ev.allDay) {
-    document.getElementById('ev-start-date').value = ev.start.slice(0, 10);
+    setDtValue('ev-start-date', ev.start.slice(0, 10), 'date');
-    document.getElementById('ev-end-date').value   = ev.end.slice(0, 10);
+    setDtValue('ev-end-date',   ev.end.slice(0, 10),   'date');
     toggleAlldayFields(true);
   } else {
     const s = new Date(ev.start);
     const e = new Date(ev.end);
-    document.getElementById('ev-start').value = toLocalDatetimeInput(s);
+    setDtValue('ev-start', toLocalDatetimeInput(s), 'datetime');
-    document.getElementById('ev-end').value   = toLocalDatetimeInput(e);
+    setDtValue('ev-end',   toLocalDatetimeInput(e), 'datetime');
     toggleAlldayFields(false);
   }
 
@@ -781,6 +794,24 @@ function bindEventModal() {
     toggleAlldayFields(e.target.checked);
   });
 
+  // Date/time pickers
+  [
+    { displayId: 'ev-start-display',      inputId: 'ev-start',      mode: 'datetime' },
+    { displayId: 'ev-end-display',        inputId: 'ev-end',        mode: 'datetime' },
+    { displayId: 'ev-start-date-display', inputId: 'ev-start-date', mode: 'date'     },
+    { displayId: 'ev-end-date-display',   inputId: 'ev-end-date',   mode: 'date'     },
+  ].forEach(({ displayId, inputId, mode }) => {
+    const disp = document.getElementById(displayId);
+    if (!disp) return;
+    const open = async () => {
+      const current = document.getElementById(inputId)?.value || '';
+      const result  = await openDatePicker(disp, current, mode);
+      if (result !== null) setDtValue(inputId, result, mode);
+    };
+    disp.addEventListener('click', open);
+    disp.addEventListener('keydown', e => { if (e.key === 'Enter' || e.key === ' ') open(); });
+  });
+
   // Color picker: click preview to open gradient picker
   const evColorPreview = document.getElementById('ev-color-preview');
   const evColorHex = document.getElementById('ev-color-hex');

frontend/js/date-picker.js

@@ -0,0 +1,271 @@
+/**
+ * Custom dark date/time picker
+ * openDatePicker(anchor, value, mode) → Promise<string|null>
+ *   anchor : DOM element to position near
+ *   value  : ISO string ("YYYY-MM-DDTHH:MM" | "YYYY-MM-DD") or ""
+ *   mode   : 'datetime' | 'date'
+ */
+import { t } from './i18n.js';
+
+const ITEM_H  = 40;  // px per scroll item
+const VISIBLE = 3;   // visible items in time scroller
+
+export function openDatePicker(anchor, value, mode = 'datetime') {
+  return new Promise(resolve => {
+    // ── Parse initial value ───────────────────────────────
+    let selDate = new Date();
+    selDate.setHours(0, 0, 0, 0);
+    let selHour = selDate.getHours();
+    let selMin  = 0;
+
+    if (value) {
+      try {
+        const raw = mode === 'datetime'
+          ? value.replace(' ', 'T')
+          : value + 'T00:00:00';
+        const d = new Date(raw);
+        if (!isNaN(d)) {
+          selDate = new Date(d.getFullYear(), d.getMonth(), d.getDate());
+          if (mode === 'datetime') { selHour = d.getHours(); selMin = d.getMinutes(); }
+        }
+      } catch (_) {}
+    }
+
+    let viewYear  = selDate.getFullYear();
+    let viewMonth = selDate.getMonth();
+
+    // ── Build DOM ─────────────────────────────────────────
+    const overlay = document.createElement('div');
+    overlay.className = 'dtp-overlay';
+    document.body.appendChild(overlay);
+
+    const card = document.createElement('div');
+    card.className = 'dtp-card';
+    overlay.appendChild(card);
+
+    function done(result) {
+      overlay.remove();
+      resolve(result);
+    }
+
+    // Click outside → cancel
+    overlay.addEventListener('mousedown', e => {
+      if (e.target === overlay) done(null);
+    });
+
+    // ── Calendar builder ──────────────────────────────────
+    function buildCalendar() {
+      const months  = t('months');
+      const dowKeys = t('dow_monday'); // always Monday-first in calendar
+
+      const firstDay  = new Date(viewYear, viewMonth, 1);
+      const gridStart = new Date(firstDay);
+      let dow = firstDay.getDay();
+      dow = dow === 0 ? 6 : dow - 1; // 0=Mon…6=Sun
+      gridStart.setDate(gridStart.getDate() - dow);
+
+      const cells = [];
+      const iter  = new Date(gridStart);
+      for (let i = 0; i < 42; i++) {
+        cells.push(new Date(iter));
+        iter.setDate(iter.getDate() + 1);
+      }
+
+      const today = new Date(); today.setHours(0, 0, 0, 0);
+
+      const dowHtml  = dowKeys.map(d => `<div class="dtp-dow">${d}</div>`).join('');
+      const daysHtml = cells.map(cell => {
+        const isOther    = cell.getMonth() !== viewMonth;
+        const isToday    = cell.getTime() === today.getTime();
+        const isSelected = cell.getTime() === selDate.getTime();
+        let cls = 'dtp-day';
+        if (isOther)    cls += ' other';
+        if (isToday)    cls += ' today';
+        if (isSelected) cls += ' selected';
+        return `<div class="${cls}" data-ts="${cell.getTime()}">${cell.getDate()}</div>`;
+      }).join('');
+
+      return `<div class="dtp-cal-header">
+        <button class="dtp-nav-btn" id="dtp-prev">&#8249;</button>
+        <span class="dtp-month-label">${months[viewMonth]} ${viewYear}</span>
+        <button class="dtp-nav-btn" id="dtp-next">&#8250;</button>
+      </div>
+      <div class="dtp-grid">
+        ${dowHtml}
+        ${daysHtml}
+      </div>`;
+    }
+
+    // ── Time scroll builder ───────────────────────────────
+    function buildTime() {
+      if (mode !== 'datetime') return '';
+      const hItems = Array.from({ length: 24 }, (_, i) =>
+        `<div class="dtp-ti" data-val="${i}">${String(i).padStart(2,'0')}</div>`
+      ).join('');
+      const mItems = Array.from({ length: 60 }, (_, i) =>
+        `<div class="dtp-ti" data-val="${i}">${String(i).padStart(2,'0')}</div>`
+      ).join('');
+      return `<div class="dtp-time-row">
+        <div class="dtp-tc-wrap">
+          <div class="dtp-tc" id="dtp-h">${hItems}</div>
+        </div>
+        <div class="dtp-colon">:</div>
+        <div class="dtp-tc-wrap">
+          <div class="dtp-tc" id="dtp-m">${mItems}</div>
+        </div>
+      </div>`;
+    }
+
+    // ── Render ────────────────────────────────────────────
+    function render() {
+      card.innerHTML =
+        buildCalendar() +
+        buildTime() +
+        `<div class="dtp-actions">
+          <button class="btn btn-ghost btn-sm" id="dtp-cancel">${t('cancel')}</button>
+          <button class="btn btn-primary btn-sm" id="dtp-ok">${t('save')}</button>
+        </div>`;
+
+      bindEvents();
+      if (mode === 'datetime') initScrollers();
+      positionCard();
+    }
+
+    // ── Event bindings ────────────────────────────────────
+    function bindEvents() {
+      card.querySelector('#dtp-prev').onclick = () => {
+        viewMonth--;
+        if (viewMonth < 0) { viewMonth = 11; viewYear--; }
+        render();
+      };
+      card.querySelector('#dtp-next').onclick = () => {
+        viewMonth++;
+        if (viewMonth > 11) { viewMonth = 0; viewYear++; }
+        render();
+      };
+
+      // Day click
+      card.querySelectorAll('.dtp-day').forEach(el => {
+        el.addEventListener('click', () => {
+          selDate = new Date(parseInt(el.dataset.ts));
+          if (el.classList.contains('other')) {
+            viewYear  = selDate.getFullYear();
+            viewMonth = selDate.getMonth();
+          }
+          render();
+        });
+      });
+
+      card.querySelector('#dtp-cancel').onclick = () => done(null);
+      card.querySelector('#dtp-ok').onclick = () => done(buildResult());
+    }
+
+    // ── Time scroll initialisation ────────────────────────
+    function initScrollers() {
+      const hCol = card.querySelector('#dtp-h');
+      const mCol = card.querySelector('#dtp-m');
+      if (!hCol || !mCol) return;
+
+      // Scroll to selected value (padding-top = ITEM_H, so scrollTop = val * ITEM_H)
+      hCol.scrollTop = selHour * ITEM_H;
+      mCol.scrollTop = selMin  * ITEM_H;
+      highlightItems(hCol, selHour);
+      highlightItems(mCol, selMin);
+
+      let hTimer, mTimer;
+
+      hCol.addEventListener('scroll', () => {
+        clearTimeout(hTimer);
+        hTimer = setTimeout(() => {
+          selHour = Math.max(0, Math.min(23, Math.round(hCol.scrollTop / ITEM_H)));
+          hCol.scrollTop = selHour * ITEM_H;
+          highlightItems(hCol, selHour);
+        }, 80);
+      });
+
+      mCol.addEventListener('scroll', () => {
+        clearTimeout(mTimer);
+        mTimer = setTimeout(() => {
+          selMin = Math.max(0, Math.min(59, Math.round(mCol.scrollTop / ITEM_H)));
+          mCol.scrollTop = selMin * ITEM_H;
+          highlightItems(mCol, selMin);
+        }, 80);
+      });
+
+      // Click item to select
+      hCol.querySelectorAll('.dtp-ti').forEach((el, i) => {
+        el.addEventListener('click', () => {
+          selHour = i;
+          hCol.scrollTo({ top: i * ITEM_H, behavior: 'smooth' });
+          highlightItems(hCol, i);
+        });
+      });
+      mCol.querySelectorAll('.dtp-ti').forEach((el, i) => {
+        el.addEventListener('click', () => {
+          selMin = i;
+          mCol.scrollTo({ top: i * ITEM_H, behavior: 'smooth' });
+          highlightItems(mCol, i);
+        });
+      });
+    }
+
+    function highlightItems(col, val) {
+      col.querySelectorAll('.dtp-ti').forEach((el, i) => {
+        el.classList.toggle('selected', i === val);
+      });
+    }
+
+    // ── Result builder ────────────────────────────────────
+    function buildResult() {
+      const y  = selDate.getFullYear();
+      const mo = String(selDate.getMonth() + 1).padStart(2, '0');
+      const dd = String(selDate.getDate()).padStart(2, '0');
+      if (mode === 'date') return `${y}-${mo}-${dd}`;
+      const h  = String(selHour).padStart(2, '0');
+      const mi = String(selMin).padStart(2, '0');
+      return `${y}-${mo}-${dd}T${h}:${mi}`;
+    }
+
+    // ── Positioning ───────────────────────────────────────
+    function positionCard() {
+      const r  = anchor.getBoundingClientRect();
+      const cw = card.offsetWidth  || 280;
+      const ch = card.offsetHeight || 420;
+      let left = r.left;
+      let top  = r.bottom + 6;
+      if (left + cw > window.innerWidth  - 8) left = window.innerWidth  - cw - 8;
+      if (top  + ch > window.innerHeight - 8) top  = r.top - ch - 6;
+      if (left < 8) left = 8;
+      if (top  < 8) top  = 8;
+      card.style.left = left + 'px';
+      card.style.top  = top  + 'px';
+    }
+
+    render();
+  });
+}
+
+/**
+ * Format an ISO value for display in the UI
+ * mode: 'datetime' | 'date'
+ * lang: 'de' | 'en'
+ */
+export function formatDtDisplay(isoStr, mode, lang = 'de') {
+  if (!isoStr) return '—';
+  try {
+    const d = mode === 'datetime'
+      ? new Date(isoStr.replace(' ', 'T'))
+      : new Date(isoStr + 'T00:00:00');
+    if (isNaN(d)) return isoStr;
+    const locale = lang === 'en' ? 'en-GB' : 'de-CH';
+    if (mode === 'datetime') {
+      return d.toLocaleString(locale, {
+        day: '2-digit', month: '2-digit', year: 'numeric',
+        hour: '2-digit', minute: '2-digit', hour12: false,
+      });
+    }
+    return d.toLocaleDateString(locale, {
+      day: '2-digit', month: '2-digit', year: 'numeric',
+    });
+  } catch (_) { return isoStr; }
+}

frontend/js/views/month.js

@@ -1,8 +1,8 @@
 import { isToday, isPast, dayOfWeek, getISOWeekNumber } from '../utils.js';
 import { t } from '../i18n.js';
 
-const LANE_H    = 20; // px per lane (height 18px + 2px gap)
+const LANE_H    = 20; // px per lane (event height 18px + 2px gap)
-const MAX_LANES = 3;  // max visible event lanes per row
+const MAX_LANES = 3;  // max visible lanes per row
 
 export function renderMonth(container, currentDate, events, onDayClick, onEventClick, weekStartDay = 'monday') {
   const year  = currentDate.getFullYear();
@@ -24,10 +24,8 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
 
   // Normalize each event's date range once
   const normed = events.map(ev => {
-    const s = new Date(ev.start);
+    const s = new Date(ev.start); s.setHours(0, 0, 0, 0);
-    s.setHours(0, 0, 0, 0);
+    const e = new Date(ev.end);   e.setHours(0, 0, 0, 0);
-    const e = new Date(ev.end);
-    e.setHours(0, 0, 0, 0);
     if (ev.allDay && e > s) e.setDate(e.getDate() - 1); // exclusive → inclusive
     return { ev, ns: s, ne: e };
   });
@@ -52,11 +50,10 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
       const colStart = Math.max(0, daysBetween(rowStart, ns));
       const colEnd   = Math.min(6, daysBetween(rowStart, ne));
       if (colEnd < colStart) return;
-      const span = colEnd - colStart + 1;
       rowItems.push({
         ev,
         colStart,
-        span,
+        span: colEnd - colStart + 1,
         continuesLeft:  ns < rowStart,
         continuesRight: ne > rowEnd,
       });
@@ -71,7 +68,7 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
     });
 
     // Assign lanes (greedy interval packing)
-    const lanes = []; // { colEnd }
+    const lanes = [];
     rowItems.forEach(item => {
       let laneIdx = lanes.findIndex(l => item.colStart >= l.colEnd);
       if (laneIdx === -1) { laneIdx = lanes.length; lanes.push({ colEnd: 0 }); }
@@ -89,7 +86,7 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
       }
     });
 
-    // Render event spans
+    // Render event spans HTML (placed in overlay)
     let eventsHtml = '';
     rowItems.forEach(item => {
       if (item.lane >= MAX_LANES) return;
@@ -110,25 +107,23 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
         title="${escAttr(ev.title)}">${escHtml(label)}</div>`;
     });
 
-    // Render "+N more" per column
+    // "+N more" per column
     Object.entries(overflowByCol).forEach(([col, count]) => {
       const c = parseInt(col);
-      const leftPct  = (c / 7) * 100;
-      const widthPct = (1 / 7) * 100;
       eventsHtml += `<div class="month-more"
         data-date="${dateKey(rowCells[c])}"
-        style="left:${leftPct.toFixed(3)}%;width:${widthPct.toFixed(3)}%;bottom:2px">${t('more_events', { n: count })}</div>`;
+        style="left:${((c / 7) * 100).toFixed(3)}%;width:${(100 / 7).toFixed(3)}%;bottom:2px">${t('more_events', { n: count })}</div>`;
     });
 
-    // Day cells (numbers only)
+    // Full-height column divs (click targets + borders)
-    let dayCellsHtml = '';
+    let colsHtml = '';
     rowCells.forEach(cell => {
       const key      = dateKey(cell);
       const isOther  = cell.getMonth() !== month;
       const todayCls = isToday(cell) ? 'today' : '';
       const otherCls = isOther       ? 'other-month' : '';
       const numCls   = isToday(cell) ? 'today' : '';
-      dayCellsHtml += `<div class="month-cell ${todayCls} ${otherCls}" data-date="${key}">
+      colsHtml += `<div class="month-col ${todayCls} ${otherCls}" data-date="${key}">
         <div class="cell-day ${numCls}">${cell.getDate()}</div>
       </div>`;
     });
@@ -136,8 +131,8 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
     bodyHtml += `<div class="month-row">
       <div class="month-kw-cell">${kw}</div>
       <div class="month-row-right">
-        <div class="month-day-strip">${dayCellsHtml}</div>
+        ${colsHtml}
-        <div class="month-events-area">${eventsHtml}</div>
+        <div class="month-events-overlay">${eventsHtml}</div>
       </div>
     </div>`;
   }
@@ -147,7 +142,7 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
     <div class="month-body">${bodyHtml}</div>
   </div>`;
 
-  // Click handlers — event delegation
+  // Click handlers via event delegation on the body
   const body = container.querySelector('.month-body');
   body.addEventListener('click', e => {
     // Span event click
@@ -158,17 +153,17 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
       if (ev) onEventClick(ev, spanEl);
       return;
     }
-    // "+N more" click → day view
+    // "+N more" → navigate to day view
     const moreEl = e.target.closest('.month-more');
     if (moreEl) {
       e.stopPropagation();
       onDayClick(new Date(moreEl.dataset.date + 'T00:00:00'));
       return;
     }
-    // Day cell click → day view
+    // Column click → navigate to day view
-    const cellEl = e.target.closest('.month-cell');
+    const colEl = e.target.closest('.month-col');
-    if (cellEl) {
+    if (colEl) {
-      onDayClick(new Date(cellEl.dataset.date + 'T00:00:00'));
+      onDayClick(new Date(colEl.dataset.date + 'T00:00:00'));
     }
   });
 }
@@ -176,7 +171,6 @@ export function renderMonth(container, currentDate, events, onDayClick, onEventC
 // ── Helpers ───────────────────────────────────────────────
 
 function daysBetween(a, b) {
-  // Number of whole days from date a to date b (can be negative)
   return Math.round((b - a) / 86400000);
 }