If you’ve made changes to events in your calendar but subscribers aren’t seeing the updates in their personal calendar applications, this is typically due to refresh delays inherent to different calendar services.
Understanding Calendar Sync Delays
When you update events in your calendar, the changes don’t appear instantly in subscribers’ calendars. Each calendar service has its own refresh schedule for subscribed calendars (iCal feeds).
Google Calendar Refresh Times
Google Calendar is particularly slow to refresh subscribed calendars:
Typical delay: 6-8 hours
Maximum delay: Up to 24 hours
No manual refresh option for subscribed calendars
This means if you update an event at 9 AM, Google Calendar subscribers might not see the changes until 3 PM or later.
Other Calendar Services
Apple Calendar (iCal):
Usually refreshes every 1-2 hours
Can be manually refreshed by the user
Microsoft Outlook:
Typically refreshes every 1-6 hours
Refresh frequency varies by account type
Other calendar apps:
Most third-party apps refresh every 1-4 hours
Some allow users to set custom refresh intervals
Why These Delays Exist
Calendar services implement these delays to:
Reduce server load and bandwidth usage
Prevent excessive API calls
Optimize performance for millions of users
What You Can Do
For Calendar Owners
Plan ahead: Make event changes well in advance when possible
Communicate directly: For urgent changes, notify subscribers via email or other channels
Set expectations: Inform subscribers about potential delays when they subscribe
For Subscribers
Be patient: Allow 6-24 hours for changes to appear in Google Calendar
Check the source: Visit the original calendar link to see immediate updates
Use multiple methods: Don’t rely solely on calendar subscriptions for time-sensitive events
Troubleshooting Update Issues
If updates aren’t appearing after 24 hours:
Verify the changes were saved in your original calendar
Check if the subscription is still active - subscribers may have unsubscribed
Test with a different calendar service to isolate the issue
Contact support if the problem persists across multiple services