Alarm was working great up untill a month ago. I've missed early appointments because the alarm doesn't go off. I've tested the alarm while wide awake for a few minutes ahead of the now time, and no alarm! What is going on? Ok so I went to my settings, app management, clock. I did an update on clock and then went back and reset my alarm for 2 minutes ahead and my alarm went off. So I'm guessing you need to update when necessary to keep the alarm working properly. I hope this review helps.