https://apps.nextcloud.com/apps/davx5_caldav_carddav_sync_suite_on_android
DAVx5 – CalDAV / CardDAV Sync Suite on Android - Apps - App Store - Nextcloud
The Nextcloud App Store - Upload your apps and install new apps onto your Nextcloud
on androidapp storecaldavcarddavsync
https://forums.zimbra.org:443/viewforum.php?f=22&sid=ea9cc925f1d43d81ad6a5a0fb17df7cf
CalDAV / CardDAV / iSync - Zimbra Forums
caldavcarddavzimbraforums
https://git.ddd.rip/ptrcnull/webvtodo
ptrcnull/webvtodo: simple no-javascript web app for editing CalDAV/VTODO lists - Forgejo
webvtodo - simple no-javascript web app for editing CalDAV/VTODO lists
web appsimplejavascripteditingcaldav
https://www.davx5.com/
CalDAV, CardDAV and WebDAV for Android
DAVx⁵ is a CalDAV/CardDAV management and sync app for Android. It also provides access to your WebDAV Cloud files.
for androidcaldavcarddavwebdav
https://datatracker.ietf.org/doc/html/rfc6638
RFC 6638 - Scheduling Extensions to CalDAV
Scheduling Extensions to CalDAV (RFC 6638, )
rfcschedulingextensionscaldav
https://forums.zimbra.org/viewforum.php?f=22&sid=5de30ce27744abff92bab936a2f1e2a2
CalDAV / CardDAV / iSync - Zimbra Forums
caldavcarddavzimbraforums