Calendar and Contact app that supports CALDAV and CARDAV?

I have an email appliance that I use to host email for a group. It does great as an email server but does not offer a web access portal. I was eploring using nextcloud as a means to provide that functionality.

I have email working fine.

The server supports caldav and cardav to allow sync. It seems the stock calendar app can act as a server but not a client. Anyone have suggestions on an available app that would act as a caldav (caendar) and cardav (contacts) client that would then be available via the nextcloud interface?

The Nextcloud calendar app cannot act as a server because it is a client app primarily to connect to the Nextcloud core system which provides the server functionality. Afaik it is possible to subscribe to external ics calendars too, but why should you do this when Nextcloud is your save harbor for your data :wink:
Until now I’m not aware about any alternate calendar or contacts app for Nextcloud.

Search for DAVx5. It syncs CalDAV/CardDAV in tour Android and, then, your native (and ugly) calendar will works (I guess).
For a Calendar and AddressBook (clients/android) I suggest the simple and minimal (and beautiful dark/amoled theme) “Simple Calendar” and “Simple Notes”, by simplemobiletools/TiborKaputa