Iphone Alarm
According to what I was able to investigate, the alarm turns off by itself after 15 minutes of ringing.
However, I have insisted with the developers at Apple that they provide the possibility of setting how long you want the alarm to turn off. For example after 30 seconds, a minute etc...
I've seen this feature in other brands and it's very convenient.
Best regards,
Mosaco55
iPhone 12 Pro, iOS 17