for me it's pretty simple...got work to do i'll stay back...if nothing to do i'll just sit for another half an hour n then go off....wat i think is tat u dun have any obligation to stay after 5 provided nothing to do larr....as for me olso doing the same....i mean in our appointment there clearly states our rightful working hours....staying back after working hours is purely on voluntarily n cannot be force 1...

just my 2 cents