I worked on a project where I crunched for well over half a year. The last 2 months were 16 hour days, which was especially annoying since the company didn't allow you to log more then 12 hours per day [ because of some legal limit to daily hours IIRC ].

What did I get in the end? A reprimand for looking bad on security review for working odd hours... by the same person assigning me the daily tasks... who would leave at 5 and give me a full days work to do by next morning (we all started at 9 daily).

Lesson learned : don't do overtime.
If they demand it, demand compensation.

Another thing I noticed was that when management leaves at 5, they don't see people working anymore, and they act like as if everyone is done working at the same time.
By not doing overtime simply by request (which is quickly out of mind) they are forced to be aware of it by authorizing the compensation.

I don't mean onesey twosey rare and incidental overtime, I mean the 'this is how things are' overtime.

-scheherazade