When I went to New Mexico, it was a 2 hour time difference, so I was going to bed at around 8 o'clock there (After a day of 7-12 miles of hiking) tired as hell. Eventually got used to the time difference, started going to bed later, and now, since I am back in PA, I am going to bed at about 1 to 2 every night and waking up at 7. Bad news all around.