Have a 2012 13" MBP. Live in NY. Travelled to California and the time automatically changed to Pacific time. Been back for a couple of weeks now and the time hasn't changed back to Eastern. I held off changing it manually to see if it would change but it didn't. Went into the time/date screen, clicked update location and it said couldn't update at this time. This happened several times. I changed it manually but any idea why that would have happened?