[jon-wood]

Given the "before dawn" constraint here I'm going to assume this is somehow related to home/building automation, in which case you should go look at Home Assistant, which has built in support for things like "do this every hour, or 20 minutes after device X was triggered" and indeed "do this 30 minutes before sunrise".

[lep]

Well it's a mixed bag. The dusk/dawn stuff would just be like nice-to-have. I would like to be reminded 30m before dawn to for example walk the dog while the sun is _just_ still out. The other for example could be used for handling "social" events. Like some games only happen during evening hours where i check more often than in off-hours but if any game happens whenever i would like to handle it after the regular game time.

Now, nothing of that would be too hard to implement myself but these task runners pop up every so often and i would like to leverage other peoples work. Home assistant just feels a bit big for this. Do note that i currently do neither of those but i always try to evaluate these use-cases for these task-runners.

[powvans]

Celery supports solar scheduling, though it's not obvious how you would do +/- some time from the solar event. You would probably need to extend their implementation, but I don't think that would be too hard.

https://docs.celeryq.dev/en/stable/reference/celery.schedule...

EDIT: I think you just need to provide a nowfun that offsets datetime.now() by the desired timedelta.

[orwin]

https://sunrise-sunset.org/api

I used this myself for my father's chicken coop, it's quite easy to use.

[lep]

Thanks but computing the time aint the hard part (modules are available for many languages). I'm more interested in how easy it is to fit this task into the scheduler.

[xani_]

Well, unless you like running in rain you'd have to feed it weather info too.

On other side it would allow it to be fancy, like rescheduling it earlier if rain is close to the sunset