Get yourself a regular alarm clock if you want to rely less on your phone.

Just put your phone on your dresser instead of by your bed.

You could always write one, it's a trivial program.

If it's for waking up at a scheduled time, why not go with a dedicated alarm clock that only needs a wall plug and maybe a backup battery?

https://f-droid.org/packages/com.sweak.qralarm/

I would just use an old phone, either yours or maybe from your family. A dedicated alarm clock that stays at home and is always charged. It has only one job: alarming. No need to make yourself dependent on a random online website. This can be done offline.

Datetime.app is a self-hostable web page with a bunch of time-related tools. I don't think it has an alarm clock so it won't help you with this need, but i mention it in case you have other date/time tool needs.

https://f-droid.org/packages/com.best.deskclock

I like this one because I can shake and flip over my phone to snooze and dismiss the alarm. Comes in handy when I'm in bed and just slap the phone or just shake it while still in my pocket to turn it off

I used the default Android (not Google) clock for setting alarms for a while, since that's what I had when I installed GrapheneOS.

But I feel you about wanting to not doomscroll, which I also took great efforts to get rid of. This resulted in me getting a cheap Casio watch that had an alarm setting, and now my wristwatch is my alarm.

Hope you find something that works for you!

Sounds like bunnie would have got you, but that was half a generation ago:

https://en.wikipedia.org/wiki/Chumby?wprov=sfla1

I feel like people might be misunderstanding the request. Are you after something like AlarmPi?

I prefer this one:

https://github.com/BlackyHawky/Clock