Originally Posted by moon

I guess I understand that one, there probably is a line somewhere as to when it becomes unreasonable.

You did remind me of why they can't assign the 4 am without a confirmation. You need to have knowledge of what your assignment is the following day before entering 10 hours of rest and if you don't confirm they don't know if you had knowledge of it and thus call you at midnight to put you into 10 hours of rest.