External calendar sync pulls events from another calendar into one of your AddCal calendars. You give AddCal the public feed URL of an external calendar (an ICS / iCal feed), and AddCal reads that feed and creates matching events on your calendar. From then on it keeps them in step automatically, so you maintain the source calendar in one place and your subscribers see the events here.
External calendar sync is a premium feature. You need an active subscription to add or update a synced calendar.
What you can sync
You sync from a feed URL, not from a provider account. Any calendar that publishes a public ICS / iCal feed (a URL starting with http:// or https://) can be the source. AddCal reads the events from that feed and copies them onto your calendar.
For step-by-step instructions on finding the feed URL for the two most common providers, see Sync external Google Calendar and Sync Outlook / Office 365 calendar.
Add a synced calendar
Open the calendar you want to sync events into.
Go to its external calendar sync settings.
Paste the external feed URL (it must start with
http://orhttps://).Give the synced calendar a name (and an optional description) so you can recognise the source later.
Save. AddCal validates the feed, then starts the first sync straight away.
You can sync one external calendar into each AddCal calendar. If a calendar already has an external calendar configured, update that one instead of adding a second.
Sync frequency and the update delay
After the first sync, AddCal re-syncs every enabled external calendar automatically once an hour. Changes you make in the source calendar (new events, edits, cancellations) appear on your AddCal calendar after the next hourly sync.
There is then a second delay before those changes reach people who already added your calendar to their own device. Subscribers receive updates on their own refresh schedule, not instantly. See Calendar subscriber update delay for how that works.
You can also pause syncing. When sync is turned off for an external calendar, AddCal stops pulling changes from the feed until you turn it back on.
Collect RSVPs on synced events
You can turn on RSVPs for the events that come in from a synced calendar, the same way you would for events you create in AddCal. When you enable RSVPs for a synced calendar you can:
Attach a custom RSVP form so you collect the details you need from each attendee.
Set how you are notified of RSVPs: off, instant, daily, or weekly.
Send each attendee a confirmation when they RSVP.
Send reminders before the event: a number of days before (from 1 to 7) and a number of hours before (from 1 to 23).
When you change these RSVP settings, you can choose to apply them to events that have already been synced, not just to events that arrive in future syncs. For more on building the form itself, see custom RSVP forms, and for the notification options see RSVP confirmations, reminders, and notifications.
Remove a synced calendar
Removing a synced calendar stops the sync and deletes all the events it brought in. The events that came from the external feed are removed from your AddCal calendar along with the connection. This does not change anything in the original source calendar.
If you only want to stop new changes coming in but keep the events that are already there, turn off syncing instead of removing the calendar.
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