If my clock app didn’t have the option to set alarms for days of the week I’d be fooked. I can tell it to ring every Monday-Thursday (the days I have class) and then not have to worry about turning it on and off every day or for the weekend. If I need turn it off for a day it will auto turn on the next day. Otherwise I’d have slept through so many days of work and school by forgetting to turn on my damned alarm I swear.