The Daylight Saving Time bug was discovered a few weeks ago when New Zealand and Australia switched to daylight saving time. The bug caused reoccurring alarms to go off an hour early.
Unfortunately for European users who are ending daylight saving time the bug causes their alarms go off an hour late.
Daylight saving time ends in the United States and Canada on November 7th. If Apple doesn't provide a fix by then, be careful you don't sleep in!