Since the OT7 update the alarm clock isn't working right. I have several alarms set for getting up, waking the kids, leaving, etc that are set to run M-F and they worked prefect till that update. Then they stopped working completely. To fix the issue I had to delete all alarms, then create them all over again. This fixed the issue , but till I figured that out I almost gave up using this phone as my daily.
BTW I am running it on a Nexus 5