ICS Import

Each provider tucks the export away in a slightly different place:

• Google Calendar: Settings → Import & export → Export (one .ics per calendar, zipped).
• Outlook / Microsoft 365: Calendar → Settings → Shared calendars → publish or export.
• Apple Calendar: File → Export → Export, per calendar.
• Proton Calendar: Settings → Calendars → export each calendar.

If you have a Google account, you can skip the manual export and let Google Sync keep your calendars mirrored automatically instead.

In Cirrux Mail, go to Settings → Sync & Import, click Upload ICS file under ICS file import, pick the destination calendar and select the .ics file. You can import into any calendar you own. To keep the events separate, first create a new calendar in Cirrux Calendar (Create calendar in the menu next to your mailbox in the sidebar). You get an email when the import is done.

All events in the file are added to the chosen calendar, including recurring events and their exceptions. Past events come across too, so your history stays searchable. For imported events, no emails will be sent to participants.

An .ics import is a one-time copy, not a live link. Changes you make later in the old calendar won’t flow through. When you upload an updated file into the same calendar, events are matched on their unique event id and the ones already in Cirrux are skipped, so changes to those events are not picked up either.

If your old provider can publish a calendar as a link, you can subscribe to that link instead with Subscribe by URL in Cirrux Calendar. A subscribed calendar is read-only and Cirrux refreshes it regularly, as long as the link stays online. See Subscribe to someone else’s calendar for where to find it.