fix: CalDAV TZID parsing + recurring event icon on all providers

- Add icalTimeToUtcDate() helper to Apple/Synology parsers that
  correctly converts ICAL.Time with unresolved TZIDs to UTC dates
  (fixes +1h shift on Synology/Apple recurring events across DST)
- Add recurring icon (Repeat) to bottom-right of all calendar event
  blocks when event.isRecurring is true

v1.63.2

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.63.1",
+  "version": "1.63.2",
   "description": "A web-based weekly task management application that organizes to-dos and calendar events in a single, intuitive weekly view",
   "main": "index.js",
   "scripts": {

src/app/globals.css

@@ -2491,6 +2491,7 @@ h3 {
 
 /* Calendar Events in Day Column */
 .weekly-calendar-event {
+  position: relative;
   padding: 0.5rem 1rem;
   border-left: 3px solid var(--weekly-teal);
   background: #f8fafa;

src/components/WeeklyView.tsx

@@ -7636,6 +7636,17 @@ export default function WeeklyView() {
                                                     >
                                                         {event.title}
                                                     </div>
+                                                    {event.isRecurring && (
+                                                        <Repeat
+                                                            size={12}
+                                                            style={{
+                                                                position: "absolute",
+                                                                bottom: 3,
+                                                                right: 5,
+                                                                opacity: 0.5,
+                                                            }}
+                                                        />
+                                                    )}
                                                 </div>
                                             );
                                         })}

src/lib/apple-calendar.ts

@@ -1,6 +1,32 @@
 import { DAVClient } from 'tsdav';
 import ICAL from 'ical.js';
 
+/**
+ * Convert an ICAL.Time to a proper UTC JS Date, handling unresolved TZIDs.
+ */
+function icalTimeToUtcDate(icalTime: any, tzid?: string): Date {
+  const jsDate = icalTime.toJSDate();
+  if (!tzid || tzid === 'UTC' || tzid === 'Z') return jsDate;
+  if (icalTime.zone && icalTime.zone !== ICAL.Timezone.utcTimezone && icalTime.zone !== ICAL.Timezone.localTimezone) {
+    return jsDate;
+  }
+  try {
+    const localStr = `${icalTime.year}-${String(icalTime.month).padStart(2, '0')}-${String(icalTime.day).padStart(2, '0')}T${String(icalTime.hour).padStart(2, '0')}:${String(icalTime.minute).padStart(2, '0')}:${String(icalTime.second || 0).padStart(2, '0')}`;
+    const naiveUtc = new Date(localStr + 'Z');
+    const formatter = new Intl.DateTimeFormat('en-CA', {
+      timeZone: tzid, year: 'numeric', month: '2-digit', day: '2-digit',
+      hour: '2-digit', minute: '2-digit', second: '2-digit', hour12: false,
+    });
+    const parts = formatter.formatToParts(naiveUtc);
+    const get = (t: string) => parts.find(p => p.type === t)?.value || '00';
+    const actualLocal = `${get('year')}-${get('month')}-${get('day')}T${get('hour')}:${get('minute')}:${get('second')}`;
+    const offsetMs = new Date(actualLocal + 'Z').getTime() - naiveUtc.getTime();
+    return new Date(naiveUtc.getTime() - offsetMs);
+  } catch {
+    return jsDate;
+  }
+}
+
 // iCloud CalDAV Server URL
 const ICLOUD_CALDAV_URL = 'https://caldav.icloud.com';
 
@@ -283,13 +309,15 @@ export const getUpcomingEvents = async (
 
             exceptionVevents.forEach((exVevent: any) => {
               const exEvent = new ICAL.Event(exVevent);
+              const exDtStartProp = exVevent.getFirstProperty('dtstart');
+              const exTzid = exDtStartProp?.getParameter('tzid') as string | undefined;
               const recId = exVevent.getFirstPropertyValue('recurrence-id');
               if (recId) {
-                exceptionDates.add(recId.toJSDate().toISOString());
+                exceptionDates.add(icalTimeToUtcDate(recId, exTzid).toISOString());
               }
 
-              const exStart = exEvent.startDate.toJSDate();
+              const exStart = icalTimeToUtcDate(exEvent.startDate, exTzid);
-              const exEnd = exEvent.endDate.toJSDate();
+              const exEnd = icalTimeToUtcDate(exEvent.endDate, exTzid);
               const exIsAllDay = exEvent.startDate.isDate === true;
 
               if (exEnd.getTime() >= minTime && exStart.getTime() <= maxTime) {
@@ -310,14 +338,18 @@ export const getUpcomingEvents = async (
 
             // Then expand the recurrence rule
             try {
-              const duration = event.endDate.toJSDate().getTime() - event.startDate.toJSDate().getTime();
+              const dtStartProp = vevent.getFirstProperty('dtstart');
+              const dtStartTzid = dtStartProp?.getParameter('tzid') as string | undefined;
+              const startUtc = icalTimeToUtcDate(event.startDate, dtStartTzid);
+              const endUtc = icalTimeToUtcDate(event.endDate, dtStartTzid);
+              const duration = endUtc.getTime() - startUtc.getTime();
               const iter = event.iterator();
               let next;
               let safetyCount = 0;
 
               while ((next = iter.next()) && safetyCount < 500) {
                 safetyCount++;
-                const occStart = next.toJSDate();
+                const occStart = icalTimeToUtcDate(next, dtStartTzid);
                 const occEnd = new Date(occStart.getTime() + duration);
 
                 // Stop if we've gone past the range
@@ -347,8 +379,10 @@ export const getUpcomingEvents = async (
             }
           } else {
             // Simple non-recurring event
-            const start = event.startDate.toJSDate();
+            const nrDtStartProp = vevent.getFirstProperty('dtstart');
-            const end = event.endDate.toJSDate();
+            const nrTzid = nrDtStartProp?.getParameter('tzid') as string | undefined;
+            const start = icalTimeToUtcDate(event.startDate, nrTzid);
+            const end = icalTimeToUtcDate(event.endDate, nrTzid);
             const isAllDay = event.startDate.isDate === true;
 
             if (end.getTime() < minTime || start.getTime() > maxTime) return;

src/lib/synology-calendar.ts

@@ -1,6 +1,47 @@
 import { DAVClient } from 'tsdav';
 import ICAL from 'ical.js';
 
+/**
+ * Convert an ICAL.Time to a proper UTC JS Date.
+ * When ICAL.js doesn't have VTIMEZONE info, toJSDate() may treat
+ * TZID'd times as UTC. This helper detects that case and corrects it
+ * using Intl.DateTimeFormat to find the real UTC offset.
+ */
+function icalTimeToUtcDate(icalTime: any, tzid?: string): Date {
+  const jsDate = icalTime.toJSDate();
+  // If no TZID, or it's already UTC, or the zone is properly resolved, just return
+  if (!tzid || tzid === 'UTC' || tzid === 'Z') return jsDate;
+  // Check if ICAL.js actually resolved the timezone (zone !== utcTimezone when resolved)
+  if (icalTime.zone && icalTime.zone !== ICAL.Timezone.utcTimezone && icalTime.zone !== ICAL.Timezone.localTimezone) {
+    return jsDate; // Properly resolved
+  }
+  // ICAL.js didn't resolve the TZID — manually convert local time components to UTC
+  // icalTime has year, month, day, hour, minute, second as local-in-TZID values
+  // but toJSDate() treated them as UTC. We need to find the UTC offset for this TZID.
+  try {
+    // Create a date string that we can parse in the target timezone
+    const localStr = `${icalTime.year}-${String(icalTime.month).padStart(2, '0')}-${String(icalTime.day).padStart(2, '0')}T${String(icalTime.hour).padStart(2, '0')}:${String(icalTime.minute).padStart(2, '0')}:${String(icalTime.second || 0).padStart(2, '0')}`;
+    // Find what UTC time corresponds to this local time in the given timezone
+    // Use a binary search approach: start with the naive UTC interpretation and adjust
+    const naiveUtc = new Date(localStr + 'Z');
+    // Get what the local time would be at naiveUtc in the target timezone
+    const formatter = new Intl.DateTimeFormat('en-CA', {
+      timeZone: tzid, year: 'numeric', month: '2-digit', day: '2-digit',
+      hour: '2-digit', minute: '2-digit', second: '2-digit', hour12: false,
+    });
+    const parts = formatter.formatToParts(naiveUtc);
+    const get = (t: string) => parts.find(p => p.type === t)?.value || '00';
+    const actualLocal = `${get('year')}-${get('month')}-${get('day')}T${get('hour')}:${get('minute')}:${get('second')}`;
+    // The difference between what we wanted and what we got is the offset
+    const wantedMs = naiveUtc.getTime();
+    const actualMs = new Date(actualLocal + 'Z').getTime();
+    const offsetMs = actualMs - wantedMs;
+    return new Date(wantedMs - offsetMs);
+  } catch {
+    return jsDate; // Fallback
+  }
+}
+
 export interface SynologyCalendarEvent {
   id: string;
   title: string;
@@ -287,13 +328,15 @@ export const getUpcomingEvents = async (
 
             exceptionVevents.forEach((exVevent: any) => {
               const exEvent = new ICAL.Event(exVevent);
+              const exDtStartProp = exVevent.getFirstProperty('dtstart');
+              const exTzid = exDtStartProp?.getParameter('tzid') as string | undefined;
               const recId = exVevent.getFirstPropertyValue('recurrence-id');
               if (recId) {
-                exceptionDates.add(recId.toJSDate().toISOString());
+                exceptionDates.add(icalTimeToUtcDate(recId, exTzid).toISOString());
               }
 
-              const exStart = exEvent.startDate.toJSDate();
+              const exStart = icalTimeToUtcDate(exEvent.startDate, exTzid);
-              const exEnd = exEvent.endDate.toJSDate();
+              const exEnd = icalTimeToUtcDate(exEvent.endDate, exTzid);
               const exIsAllDay = exEvent.startDate.isDate === true;
 
               if (exEnd.getTime() >= minTime && exStart.getTime() <= maxTime) {
@@ -313,14 +356,18 @@ export const getUpcomingEvents = async (
             });
 
             try {
-              const duration = event.endDate.toJSDate().getTime() - event.startDate.toJSDate().getTime();
+              const dtStartProp = vevent.getFirstProperty('dtstart');
+              const dtStartTzid = dtStartProp?.getParameter('tzid') as string | undefined;
+              const startUtc = icalTimeToUtcDate(event.startDate, dtStartTzid);
+              const endUtc = icalTimeToUtcDate(event.endDate, dtStartTzid);
+              const duration = endUtc.getTime() - startUtc.getTime();
               const iter = event.iterator();
               let next;
               let safetyCount = 0;
 
               while ((next = iter.next()) && safetyCount < 500) {
                 safetyCount++;
-                const occStart = next.toJSDate();
+                const occStart = icalTimeToUtcDate(next, dtStartTzid);
                 const occEnd = new Date(occStart.getTime() + duration);
 
                 if (occStart.getTime() > maxTime) break;
@@ -344,8 +391,10 @@ export const getUpcomingEvents = async (
               console.error(`[SYNOLOGY CALENDAR] Error expanding recurrence for "${event.summary}":`, expandErr);
             }
           } else {
-            const start = event.startDate.toJSDate();
+            const nrDtStartProp = vevent.getFirstProperty('dtstart');
-            const end = event.endDate.toJSDate();
+            const nrTzid = nrDtStartProp?.getParameter('tzid') as string | undefined;
+            const start = icalTimeToUtcDate(event.startDate, nrTzid);
+            const end = icalTimeToUtcDate(event.endDate, nrTzid);
             const isAllDay = event.startDate.isDate === true;
 
             if (end.getTime() < minTime || start.getTime() > maxTime) return;