Depends on where you live I would guess....I know in B.C. the laws say you don't get OT for the tech industry.
if you are billing by the hour (as a consultant or consulting company), you can be damn sure they are getting paid for that time, so if you aren't getting some leave or other compensation, you are being taken advantage of.
That said, there is an extreme dev shortage all over. Meanwhile, projects still need to get done and there apparently ISN'T a shortage of incompetent project managers.