If your alarm is going off at the wrong time on your iPod nano or Fifth Generation iPod, make sure you are setting the alarm on the correct clock.
iPod nano and Fifth Generation iPod support multiple clocks. If you configure an alarm on your San Francisco clock for 10:00 AM, the alarm will go off at 10:00 AM Pacific Standard Time, even if you are in Austin (Central Standard Time). Make sure you set your alarms on the correct clock. To set an alarm: