Not recognizing the time change will result in the alarm being an hour early. The hour late excuse is for the change in spring.
Not the only glitch. My brother just bought the "Apple iPhone 4". When using calender function to remind him of the birthday of an old man he knows then after he has filled in the correct birth date the phone then changes the day (date) (I think) - it's not my phone so I can't remember the exact details. I just remember that he made a demonstration of the problem and I told him that that was something he should report to Apple so that they could fix it....