v0.11.3 fixed timezone issue

frontend/src/components/ScheduleManagerModal.jsx

@@ -16,13 +16,33 @@ function fmtTime(isoStr) {
   return d.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
 }
 function fmtTimeRange(start, end) { return `${fmtTime(start)} – ${fmtTime(end)}`; }
-function toLocalDateInput(isoStr) { return isoStr ? isoStr.slice(0,10) : ''; }
-function toLocalTimeInput(isoStr) { return isoStr ? isoStr.slice(11,16) : ''; }
-function buildISO(date, time) { return date && time ? `${date}T${time}:00` : ''; }
+function toLocalDateInput(isoStr) {
+  if (!isoStr) return '';
+  const d = new Date(isoStr);
+  const pad = n => String(n).padStart(2,'0');
+  return `${d.getFullYear()}-${pad(d.getMonth()+1)}-${pad(d.getDate())}`;
+}
+function toLocalTimeInput(isoStr) {
+  if (!isoStr) return '';
+  const d = new Date(isoStr);
+  const pad = n => String(n).padStart(2,'0');
+  return `${pad(d.getHours())}:${pad(d.getMinutes())}`;
+}
+function buildISO(date, time) {
+  if (!date || !time) return '';
+  const d = new Date(`${date}T${time}:00`);
+  const pad = n => String(n).padStart(2,'0');
+  const off = -d.getTimezoneOffset();
+  const sign = off >= 0 ? '+' : '-';
+  const abs = Math.abs(off);
+  return `${date}T${time}:00${sign}${pad(Math.floor(abs/60))}:${pad(abs%60)}`;
+}
 function addHours(isoStr, hrs) {
   const d = new Date(isoStr);
   d.setMinutes(d.getMinutes() + hrs * 60);
-  return d.toISOString().slice(0,19);
+  const pad = n => String(n).padStart(2,'0');
+  // Return local datetime string — do NOT use toISOString() which shifts to UTC
+  return `${d.getFullYear()}-${pad(d.getMonth()+1)}-${pad(d.getDate())}T${pad(d.getHours())}:${pad(d.getMinutes())}:00`;
 }
 function sameDay(a, b) {
   return a.getFullYear()===b.getFullYear() && a.getMonth()===b.getMonth() && a.getDate()===b.getDate();
@@ -174,8 +194,8 @@ function EventForm({ event, userGroups, eventTypes, selectedDate, onSave, onCanc
     try {
       const body = {
         title: title.trim(), eventTypeId: eventTypeId || null,
-        startAt: allDay ? `${startDate}T00:00:00` : buildISO(startDate, startTime),
-        endAt: allDay ? `${endDate}T23:59:59` : buildISO(endDate, endTime),
+        startAt: allDay ? buildISO(startDate, '00:00') : buildISO(startDate, startTime),
+        endAt: allDay ? buildISO(endDate, '23:59') : buildISO(endDate, endTime),
         allDay, location, description, isPublic, trackAvailability: trackAvail,
         userGroupIds: [...selectedGroups],
       };