[Alupis]

Good 'ol fashioned Cron will do the trick...

[preetnation]

fair option

[Alupis]

otherwise, it seems overkill to need some public API to do this.

idk what language you're working in, but for local timing issues, Quartz Scheduler is pretty good (for JVM languages). It support cron syntax as well.

https://quartz-scheduler.org/

[preetnation]

use case is for something similar to what MyFitnessPal does with user-specified reminders by time of week