Best Calendar 366 Alternatives in 2026
Updated
20 platforms from calendar apps ranked against Calendar 366 on the same published basis.
- 1Calendar 366 vs Lark
- 2Calendar 366 vs Calendar.com
- 3Calendar 366 vs Teamup
- 4Calendar 366 vs 7shifts
- 5Calendar 366 vs Slotly
- 6Calendar 366 vs Mozilla Thunderbird
- 7Calendar 366 vs Microsoft Outlook Calendar
- 8Calendar 366 vs Proton Calendar
- 9Calendar 366 vs Reclaim AI
- 10Calendar 366 vs EGroupware
- 11Calendar 366 vs Notion Calendar
- 12Calendar 366 vs Doodle
- 13Calendar 366 vs Cozi
- 14Calendar 366 vs TimeTree
- 15Calendar 366 vs Google Calendar
- 16Calendar 366 vs Tuta Calendar
- 17Calendar 366 vs Fantastical
- 18Calendar 366 vs FlowSavvy
- 19Calendar 366 vs Trevor AI
- 20Calendar 366 vs Samsung Calendar
Calendar 366 alternatives compared
| # | Platform | Score | Free plan | From | Runs on |
|---|---|---|---|---|---|
| 1 | Lark | 8.8 | Free plan | — | Android, API, iOS, Linux, Mac, Web, Windows |
| 2 | Calendar.com | 8.8 | Free plan | $20/mo | Android, API, Browser, iOS, Web |
| 3 | Teamup | 8.7 | Free plan | $12/mo | Android, API, iOS, Web |
| 4 | 7shifts | 8.1 | Free plan | Free | Android, API, iOS, Web |
| 5 | Slotly | 7.9 | Free plan | $0.83/mo | Android, API, Web |
| 6 | Mozilla Thunderbird | 7.6 | Free plan | Free | Android, Linux, Mac, Windows |
| 7 | Microsoft Outlook Calendar | 7.5 | Free plan | $1.67/mo | Android, iOS, Mac, Web |
| 8 | Proton Calendar | 7.4 | Free plan | Free | Android, iOS |
| 9 | Reclaim AI | 7.4 | Free plan | $10/mo | Browser, Web |
| 10 | EGroupware | 7.4 | No | €21.90/mo | Web, Linux, Windows, Mac |
| 11 | Notion Calendar | 7.3 | Free plan | Free | Android, iOS |
| 12 | Doodle | 7.3 | Free plan | $11/mo | Web |
| 13 | Cozi | 7.3 | Free plan | $3.25/mo | Android, iOS, Web |
| 14 | TimeTree | 7.3 | Free plan | $3.75/mo | Android, iOS, Web |
| 15 | Google Calendar | 7.2 | No | $7/mo | Android, iOS |
| 16 | Tuta Calendar | 7.2 | Free plan | €3/mo | Android, iOS |
| 17 | Fantastical | 7.2 | Free plan | Free | iOS |
| 18 | FlowSavvy | 7.2 | Free plan | — | Android, iOS, Web |
| 19 | Trevor AI | 7.2 | Free plan | $0.42/mo | Web |
| 20 | Samsung Calendar | 7.1 | Free plan | Free | Android |
Make your platform an alternative to Calendar 366
See the priceThe sponsored alternative slot on this page is labelled Sponsored.
Questions about Calendar 366 alternatives
What is the best alternative to Calendar 366?
Lark, number 1 in calendar apps with a score of 8.8 out of 10. The others here: Calendar.com, Teamup, 7shifts and 16 more.
What is the best free alternative to Calendar 366?
Lark is the best-ranked alternative with a free plan. 18 of the 20 alternatives here publish a free plan on their own pricing pages.
Is there an open-source alternative to Calendar 366?
Yes: Mozilla Thunderbird, EGroupware.
How are these alternatives ranked?
Ranked on what each maker publishes, open and connectable first: a public API, open-source code, the depth of its documentation and a free tier to try it on. Model lists are sorted by the figure in their title, exactly as each provider publishes it.