In college, a consistent 8 hours a week, usually due to having nothing better to do. After college, 6 hours every week, but we randomly skip several weeks due to the usual obligations of life. Same gaming group in both cases.
Same with our group. I'm not too bothered by it, because it's always fun to see friends.
Our sessions start usually at 16:30-17:30 and run to 10-11 at weeknights, and a little later at weekends. A year a go we regularly did sessions to 4 am, but now people have gotten jobs, babies, GFs and whatnot. (in short: LIFE )