Google Calendar syncs your schedule across devices and shares availability with other Google users. Standard CalDAV servers let you keep events and contacts on your own server and use any calendar app, instead of tying your schedule to one provider.
9 open-source alternatives to Google Calendar you can host yourself, ranked by GitHub stars and updated daily.
| # | App | Category | Stars | Language | Updated |
|---|---|---|---|---|---|
| 1 |
nextcloud/server
|
File Sync & Sharing | 37,483 | PHP | today |
| 2 |
Kozea/Radicale
|
Calendar & Contacts | 5,204 | Python | 3d |
| 3 |
sabre-io/Baikal
|
Calendar & Contacts | 3,371 | PHP | 8d |
| 4 |
Alinto/sogo
|
Groupware | 2,186 | Objective-C | today |
| 5 |
etesync/server
|
Calendar & Contacts | 1,779 | Python | 2y |
| 6 |
sabre-io/dav
|
Calendar & Contacts | 1,727 | PHP | 10d |
| 7 |
agendav/agendav
|
Calendar & Contacts | 836 | PHP | 24d |
| 8 |
tchapi/davis
|
Calendar & Contacts | 759 | PHP | 2d |
| 9 |
jelmer/xandikos
|
Calendar & Contacts | 613 | Python | today |