Compare software

Etar vs Notion Calendar: catalog facts
Etar	Notion Calendar
Free Free and open source.	Free Free to use.
Android	Windows, macOS, Android, iOS
Open source with an active community Clean Material Design interface	Free Tight integration with Notion databases and docs
Android only Sync depends on the calendar accounts set up on the phone	Built around Google Calendar and Notion Proprietary
Downloadable app	Downloadable app
Open source	Closed source
License: GPL-3.0	License not stated
Not stated if an account is needed	Not stated if an account is needed
Not stated if it works offline	Not stated if it works offline
Official website Full listing and sources Checked September 24, 2026	Official website Full listing and sources Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.