Ever since I started degoogling my life, i missed how to integrate calendar and tasks in all my devices. Because of my work Im stuck using Macos and I have a debloated samsung device with F-droid. However I need a way of syncing calendars and tasks between Macos and my phone, so I can get push notifications on both of my devices about events and pending tasks, I really need this as i often struggle with ADHD and the only way of getting my tasks done is being very structured with my apps notifying me with the tasks i need to do. Do you guys know what is the best way to implement this using FOSS software?
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