Calendar - move resize event - variables

I love the calendar. I am trying to implement the move and resize events and have a question about the event variables. It seems that the event start field gets updated right away when you move, but the end field is left blank. Is that the way it is supposed to be. I would have thought that if an event had the same start and end date before it was moved, then you move it, the event click variables would both be updated.

Please advise if I need to update the end field differently.

Thanks,
Rick