XP

Anyone who has had a very irregular sleeping schedule will know how important it is to set multiple alarms. This isn't just about being worried that you'll miss an alarm, but that you will subconsciously turn off the alarm and continue sleeping (I've done both before).

There will also be days where waking up on time is going to be super important (i.e. for a job interview). For those days you should definitely set multiple alarms. Alarms for when you want to wake up, multiple alarms incase you missed the first one, and then another one to make sure you leave on time.

If it's really important, I'd recommend setting both an analog and a digital alarm. Thus you won't have to worry about the batteries running out, a blackout (this can reset a digital alarm), subconsciously turning off one of the alarms, and other possible issues.

Alarms are also just very useful as reminders. Example: I'm meeting a friend at 4 but I don't want to leave late. I'll just set an alarm for 3:15 so I'll have enough time to prepare.