Radical, Baikal, or NextCloud.
Then sync with your phone via Davx5
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Radical, Baikal, or NextCloud.
Then sync with your phone via Davx5
Davx⁵ has Mac OS caldav carddav server integration so you can sync with it.
https://www.davx5.com/tested-with/calendar-and-contacts-server
On android you can use simple calendar or etar to view calendars and "tasks" or jtxboard for tasks/journals
If you're willing to self host Nextcloud then that could be a solution.
Currently I use it to sync my calendar on my phone and an instance of MagicMirror2.
You don't necessarily need to self-host Nextcloud for yourself, you can pay a provider to do it for you, of course, at a price, or free but with limitations, like The Good Cloud.
You can also try EteSync.
And in F-Droid there are many apps to integrate your Nextcloud instance with your device, my favorite are Ente (for calendar), Tasks(dot)org and Joplin
Nextcloud should be good for that. There are a bunch of services which offer a few GB for free, which should be enough for your needs.
I agree that Nextcloud is a great solution. Some other cardDAV and calDAV solutions exist, but Nextcloud provides much more. Here is a little demo of Nextcloud on a handset. https://videos.trom.tf/videos/watch/5fc16e0e-f95f-45a2-9843-37749bf9dada
I tried almost every possible solution suggested here, but i couldnt manage to make it work, I'd really like a simple guide on how to set something like this or a self-hosting solution, though i dont even know if i can do that without a server
I have been using simple calendar.
Try Proton Calendar