Add CalDAV Support

Hello,

My apologies if this is not the correct channel to ask this question, I have tried using a search engine for an answer, but I've had no luck.

I see that there is a Google Calendar integration available for the Planner function; is there a way to (or are there any plans to) allow integration to a CalDAV server instead? I really like the idea of syncing my events and tasks with my calendar, but I use a self hosted solution (Radicale) instead of Google Calendar.

Thank you for any assistance that you can provide.

The issue names the Planner Google Calendar integration and a self-hosted Radicale CalDAV server, but no files or tests. Start by locating the existing Google Calendar integration and determining how calendar events and tasks are synchronized. Done should be defined as an agreed CalDAV integration that supports the requested event and task syncing.

Written by the indexing model from the issue text.