Once you are hired you live for the company. 12 hours long shifts are scheduled without proper planning. You will arrive at home after doing a 12 hr night shift at 8 am and will be called at 11 am from the next shift. This happens very often.
The expectation to arrive at work 8 am even when you finished 3 am because the poor planing of the group leader, project and program managers made you stay 8 hours longer than the scheduled end for the day work.