Oh yes, know those well! I also sometime end up working in various cubby holes in ... erm ... I think I'll just describe them as "buildings in central London" without being too specific ... where there is no natural daylight at all. I've come out of one of those rooms at the end of a day persuading a server to behave to find that the bright sunny morning had turned into torrential rain and sleet and everything was pitch black.
The good things are :- 1. the overtime is paid at the moment 2. it's not lasting for too much longer 3. if we get it right the results of our system will be in use in every High Street in the land during April
(of course if it gets screwed up you'll probably hear about it in the press ... the joy of large IT projects eh?)