Why are Microsoft calendar events not deleting properly?

 

What’s happening
You delete an event in Year Glance, but it still appears in Microsoft 365 or Outlook on the web. It can look like the delete hasn’t synced but in most cases the event has been deleted in Microsoft. The issue is caused by Microsoft 365 caching, where the web app interface updates slowly or temporarily shows outdated data.

This is a known behaviour in Outlook Web and Outlook Desktop.

Technical example

Why this happens
Microsoft 365 web apps rely heavily on browser caching. Occasionally:

• The Outlook web UI does not immediately reflect a deleted event
  
• The browser holds onto cached calendar data
  
• The API briefly returns stale information
  

How to sync in the browser if it hasn't updated after a few minutes 

Try one of the following:

1. Hard refresh your browser
   
   • Windows: Ctrl + Shift + R
   • Mac: Cmd + Shift + R
2. Close and reopen the browser tab
   
3. Clear your browser cache (if the issue persists)
4. Wait a few minutes and refresh again

How to sync in the Outlook app if it hasn't updated after a few minutes 

• In Outlook app, try navigating to a different month and then back again.
• If that doesn't work, close the app and open it again.

If events continue to appear incorrectly in Year Glance
If you're seeing stale or incorrect events on the Year Glance side (rather than in Outlook), you can use the Clear Calendar Events option to remove all stored Microsoft events from Year Glance and trigger a fresh sync.

This will not affect your actual calendar data in Microsoft.

To use this, hover over your Microsoft account in the Calendar panel and click the clear icon (triangle with exclamation mark). Confirm by clicking Remove.

See: How to refresh your calendar list or clear calendar events

Summary
If the event is deleted in Year Glance but still appears in Outlook web or app, the issue is within Microsoft 365 rather than Year Glance. If the problem appears to be on the Year Glance side, clearing your calendar events will reset the local data and re-sync from Microsoft.