When a user subscribes to your AddEvent calendar, their calendar app creates a live connection to your AddEvent calendar feed using a standard iCal URL. The app periodically polls that URL for updates and syncs any changes it finds.

What syncs automatically

• New events you add to your AddEvent calendar appear in subscribers' calendars on the next sync
• Updated events - changes to title, time, location, or description are reflected automatically
• Cancelled events - removed from subscribers' calendars on the next sync

How fast do updates appear?

Sync frequency is controlled by the subscriber's calendar app, not AddEvent. Typical update windows:

Calendar app	Typical sync frequency
Google Calendar	Every 12–24 hours (Google throttles external feeds)
Apple Calendar	Every 1–24 hours (user-configurable in settings)
Outlook / Office 365	Every 1–3 hours

Forcing a faster sync: in Google Calendar on desktop, subscribers can right-click the calendar in the left sidebar and choose "Refresh" to trigger an immediate sync. In Apple Calendar, go to the calendar's settings and set the refresh interval to "Every 15 minutes."

Push notifications for faster updates (paid plans)

On paid plans, AddEvent supports calendar push notifications - a mechanism that signals subscribers' calendar apps to sync sooner when you make a change, rather than waiting for the next scheduled poll. This can significantly reduce the 12–24 hour Google delay.

What doesn't sync

Subscription calendars use the iCal standard (.ics format). Some things are outside its scope:

• Rich HTML in event descriptions (displays as plain text)
• Images embedded in calendar entries (not supported by iCal)
• Real-time push to subscribers' devices (depends on their calendar app's refresh interval)

When a subscriber unsubscribes

When a subscriber unfollows your calendar from within their calendar app, all events from your calendar are removed from their device automatically.