There is a buzz around Twitter and the Internet about an iPhone with the newest IOS 4.2.1 having a bug in the Alarm app that prevents one time alarms from working. It does not affect recurring alarms and all alarms will return to normal (bug is still there though) on Jan. 3rd. MacWorld has the official scoop from Apple:
Apple spokesperson Natalie Harrison confirmed to Macworld that Apple is aware of the problem. “We’re aware of an issue related to non repeating alarms set for January 1 or 2,” Harrison said. “Customers can set recurring alarms for those dates and all alarms will work properly beginning January 3.”
I personally use Best Alarm Clock from the app store that costs .99¢ and isn’t affected.