If I set an alarm clock with a ringtone, how long will the ringtone run if I do not stop it? If I set the iphone alarm clock with a ringtone, how long will the ringtone run if I do not stop it?

Will it run all the way until it runs out of battery and the phone shuts down?
Indefinitely, near as I can tell. I once had my phone go for over a half hour on an alarm.