*usually* this kind of stuff is reserved for the junior employees to tend to be younger with fewer obligations. They're also willing to be taken advantage of in exchange for future advancement. My college friends going into law or accounting were bracing for 60+ hr work weeks. I've heard horror stories of 80 hr work weeks. Things ease up once you've paid your dues - in theory. It's rough going in the beginning.
Heh... I was gonna tell her that the higher he moves up, he might end up in exempt positions where he has neither comp or overtime, just responsibility. I know it can be that way in the private sector, I don't know about the city.