Alternatives to Google Calendar

Google Calendar comes pre-installed on almost every Android phone and, naturally, syncs every appointment you make to Google's servers. Samsung has its own app, Microsoft has Outlook, Apple has iCloud Calendar — all convenient, all with the same underlying problem: your calendar lives on someone else's servers.

Your calendar is one of the most private things you entrust to these services: it contains medical appointments, planned trips, work meetings. The cloud alternatives here use the open CalDAV protocol, which is compatible with any device — on Android via DAVx⁵ or dedicated apps, on iOS natively. Some also offer end-to-end encryption, so not even the provider can read your events.

If you're just looking for a local calendar app with no cross-device sync, F-Droid has dozens of solid options that don't require entrusting your schedule to any cloud.