Never enough. On REALLY GOOD DAYS I'll sleep from about 10:00-10:30 to 7:00-7:30.
Most of the time though it's round midnight to 7:30.
Weekend are the only time i even come close to a good night's rest since no one wakes me up then. I'll be up after midnight and get out of bed around 11:00 am. I once slept in until 1:00 PM and was late for work. That's how responsible I am.