You can bring your AddEvent calendars and events into AddCal, but not your subscribers. Each subscriber's calendar app holds an AddEvent feed link, and only AddEvent controls it, so AddCal cannot import those subscribers or redirect them. Instead, you move your audience to your new AddCal link.
Bring your events across
In the sidebar, under Connect, open Integrations and choose AddEvent.
Enter your AddEvent API Key and click Preview Import.
Check the calendars and events it found, then click Start Import.
This is a one-time import of calendars and events. RSVPs, analytics and subscribers are not imported, and later changes in AddEvent are not synced. For more detail, see Import events.
Move your audience
Check your imported calendars and events in AddCal.
Send your subscribers the new AddCal calendar link and ask them to subscribe.
Run both calendars in parallel until most people have moved.
Cancel AddEvent. Anyone still subscribed to the AddEvent feed stops getting updates.
Combine several calendars into one link
If you had several AddEvent calendars and want one subscribe link for all of them, group them into a collection (Premium or Business). See Calendar collections. The collection has its own link and its own subscribers, so send that link to anyone who should follow the combined calendar.