Q: Calendar on MacBook Air sync issues.

I have Calander synced to iCloud on both my MacBook Air and iPhone.  When I enter an event on my MacBook Air, connect to the internet and it syncs with iCloud, it changes the event time back to 9am.  It only occurs on the MacBook Air, when entered on the iPhone it doesn't change the time.  Taken it in to Apple Geniuses.... not so Genius as they were unable to fix the problem.

Have already deleted my iCloud account on the MacBook Air and reinstalled everything and this didn't solve the problem.  Anyone have any ideas?