Alarm turned off after daylight savings change?

Hi. I woke up late this morning. I know I set my alarm last night. Last night was the change to daylight savings (forward one hour). Ok, I'm human, so of course being asleep, I can't be 100% sure I didn't turn it off without waking... we all have done that right? :P But I'm fairly certain I didn't, and am wondering if this may be a software glitch. I don't want to wait 6 months to find out when it changes back.

iPhone 4 fully updated. Alarm set to 5:30am