

CalDAV is all you need
I setup Nextcloud and then realised no one used it’s Calendar, or contacts, or basically anything - it was just being used as a sync hub for phones.
So, I ditched it for Radicale. Waaay less maintenance.
DAVx5 on the phones with Fossify Calendar & Tasks(.org) apps from FDroid.
They do all the alerting.
On the desktop Vivaldi has a good built-in Calendar, so I use that (although I’ve only just noticed it doesn’t show Tentative appointments at all)
For work, I use Logseq (for everything) & to keep a note of ToDo items that I don’t need reminders for (otherwise Tasks is overwhelming)
And for bonus points, Home Assistant has a CalDAV module so domestic things like waste collection are sync’d from Radicale too so there’s a notification on the kitchen display each morning to tell me what coloured box, bin, bag needs to be taken out today.
And… (some time management advice thst you didn’t ask for) - I’m currently starting timeboxing - so instead of creating a todo item, just schedule the time to actually do it in. Less ToDos, but more progress (I hope)
I think that’s the point (.txt)