diff --git a/package.json b/package.json
index 7432aa7..1dea7e7 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.74.7",
+  "version": "1.74.8",
   "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": {
diff --git a/src/lib/calendar-events.ts b/src/lib/calendar-events.ts
index 5762792..7ae9829 100644
--- a/src/lib/calendar-events.ts
+++ b/src/lib/calendar-events.ts
@@ -1140,6 +1140,8 @@ export const updateCalendarEvent = async (
 
     // Extract base series ID for Outlook
     const baseEventId = eventId.includes('::') ? eventId.split('::')[0] : eventId;
+    console.log(`[OUTLOOK] Updating event: originalId=${eventId}, baseEventId=${baseEventId}`);
+    console.log(`[OUTLOOK] Update payload: start=${JSON.stringify(event.start)}, end=${JSON.stringify(event.end)}, title=${event.title}`);
 
     const startDate = event.start?.dateTime ? new Date(event.start.dateTime) : new Date();
     const outlookUpdateTz = event.timezone || Intl.DateTimeFormat().resolvedOptions().timeZone || 'UTC';
diff --git a/src/lib/outlook-calendar.ts b/src/lib/outlook-calendar.ts
index 95c59c6..e6b8d54 100644
--- a/src/lib/outlook-calendar.ts
+++ b/src/lib/outlook-calendar.ts
@@ -387,6 +387,8 @@ export const updateEvent = async (
         } : {}),
     });
 
+    console.log(`[OUTLOOK] updateEvent request body:`, body);
+
     const patchHeaders: Record<string, string> = {
         'Authorization': `Bearer ${accessToken}`,
         'Content-Type': 'application/json',
@@ -400,16 +402,19 @@ export const updateEvent = async (
     let response = await fetch(`${GRAPH_ENDPOINT}/me/events/${encodedEventId}`, {
         method: 'PATCH', headers: patchHeaders, body
     });
+    console.log(`[OUTLOOK] PATCH /me/events/${eventId.slice(-20)} → ${response.status}`);
 
     if (!response.ok && (response.status === 404 || response.status === 400)) {
         // Fallback: try calendar-scoped endpoint
         response = await fetch(`${GRAPH_ENDPOINT}/me/calendars/${encodedCalendarId}/events/${encodedEventId}`, {
             method: 'PATCH', headers: patchHeaders, body
         });
+        console.log(`[OUTLOOK] PATCH fallback /me/calendars/.../events/${eventId.slice(-20)} → ${response.status}`);
     }
 
     if (!response.ok) {
         const err = await response.text();
+        console.error(`[OUTLOOK] Update failed:`, err);
         throw new Error(`Failed to update Outlook event: ${err}`);
     }