If you change events but subscribers do not see the updates in their own calendar apps, the cause is almost always the refresh schedule of the subscriber's calendar service, not a problem with your calendar.
Why the delay happens
AddCal serves your latest events every time a calendar app fetches your subscription feed. The delay comes after that. Each calendar service (Google, Apple, Outlook, and others) only re-checks a subscribed feed on its own schedule, and between those checks the app keeps showing the version it last downloaded.
The calendar provider sets these refresh schedules to reduce server load. There is no setting on AddCal's side that can force a subscriber's app to refresh sooner.
Typical refresh times by service
Service | Usual refresh | Manual refresh |
Google Calendar | About 6 to 8 hours, sometimes up to 24 hours | Not available for subscribed calendars |
Apple Calendar (iCal) | Every 1 to 2 hours | Yes, the user can refresh manually |
Microsoft Outlook | Every 1 to 6 hours, varies by account type | Varies by account type |
Other calendar apps | Every 1 to 4 hours | Some let users set a custom interval |
Google Calendar is the slowest. If you update an event at 9 AM, Google Calendar subscribers may not see the change until mid-afternoon or later.
What you can do as the calendar owner
Make event changes well in advance when you can.
For urgent changes, tell subscribers directly by email or another channel, since the feed alone may not update in time.
Set expectations when people subscribe so they know updates can take several hours to appear.
What subscribers can do
Allow up to 24 hours for changes to appear in Google Calendar.
In Apple Calendar, refresh the subscription manually to pull the latest version sooner.
Open the original calendar link to see the current events right away.
Do not rely only on the subscribed feed for time-sensitive events.
Troubleshooting updates that never arrive
If a change still has not appeared after 24 hours:
Confirm the change was saved in your AddCal calendar.
Check that the subscription is still active, in case the subscriber removed it.
Test the feed in a different calendar service to see whether the issue is specific to one app.
Contact support if the problem continues across multiple services.