alt Hacker NewsYou don’t need to build an app. You can use the built in Shortcuts app.
create a shortcut that turns off all alarms. Can have it read your calendar or whatever as signal to determine if alarms should be on/off for a certain day/time and have it run at a regular schedule.
I could, but what's the fun in that!?
(But in seriousness, I hadn't considered using shortcuts. It's not clear it's extensible enough to do exactly what I want, but I'll look into it)