Edit: I seek a server-less solution.
The only thing I can see is Linwood Flow but it looks like it’s a really, really long way off before becoming a primary calendar app.
If it could just store all calendar content in 1 local file, then that could be so easily auto-synced across devices with [email protected]. Does anyone have any leads?
Hmm, I just now learned about Fruux, in this Reddit post…
Give us an example of what you want as the end result - what devices you have, are you sharing calendars with someone else, etc.
My best answer is to run a calendar server on some machine and let your calendar sync to that whenever the devices are online on the same wifi simultaneously. (E.G. Run Owncloud in a docker on your laptop).
Alternatively you could run Tailscale on the devices which would provide a secure mesh network, eliminating the need to be on the same wifi - so long as they’re online they can sync via Tailscale.
Tailscale even has a feature (Funnel) that will route specific internet traffic into your Tailscale net - this would eliminate the need to have Tailscale on every device. You could host a calendar on a laptop (say Nextcloud in Docker with Tailscale), enable Funnel only for the calendar port, and apply security in Tailscale so only you have access.