I'm having same problem too. Has happened 3-4 times now. Can't figure out what causes the time to change to random time. At one point I thought it was caused by my leaving my calendar at a previous date or appointment, but really don't think so. I have a Verizon - iphone 5. I would think that the time would come from Verizon. Not Apple. But no one else is talking about it. Anyway, you're not alone )c: Turning it off and then back on is fine HOWEVER, last night it changed time to 2 or 3 hours EARLIER so my alarms were screwed up! I asked Siri "what time is it" and she must get her information from the iphone settings. So... she gave me the WRONG time also. Sad. 1st time it happened, it was actually Sunday 8:03 AM PST and iphone showed 11:38PM. This morning, not only was the time wrong, the date was last Tuesday, 9/26/12! Not funny when we all depend on our calendars and appointments that are set on each day. Other times, I just reset it and will wait for someone to fix the problem. I love the iphone 5 though! Nice and light (I'm a runner). It replaced a 4. Loved that one too, but new iOS6 is WAY FASTER! Love it to pieces!