At the rate things have been going for Apple lately, they're going to need to hire a specialist to deal with how their clock works in the software. This past weekend, we had to set our clocks to "spring ahead" by an hour. Most of our electronics did it themselves automatically, including our iPhones. Oddly, some of the iPhones seem to have a bad memory as they reverted back an hour, as if Daylight Saving never happened.
There's a thread on the Apple Discussions board talking about this bug. It seems that many iPhones ticked over to the Daylight Saving time correctly when it came into effect at 2 a.m., but eventually reverted within a day later. This happened on multiple carriers in both the U.S. and Canada.
Fortunately, the fix to this is easy, as all a user has to do is disable automatic time setting by carrier, reboot, and then re-enable automatic time setting. Sadly, those who didn't notice the time bug found themselves waking up an hour late for work.