well I'm a student (grad) and I get paid to do schoolwork & research.
During the summer it's about 2-4 hours a day...during school it's about 5-8 (depending on whether I have classes).
5 hours or so. I'd like to work more cause aside from working just 5 hours a day they'd sometimes send me home and it's closed every Friday for the psat 2 months. I'm supposed to be full-time (40 hours per week) but I'm working even less than part-time on some weeks (less than 20). My last paycheck covered my rent and barely covered my bills. I earned basically $0 for last month.
9-10 hours a day, 5 days a week. I'm pretty lucky that I can telecommute if I want to, but to me I'd rather be in the office around people than stuck at home by myself .
I can also work once I get home, so I tend to work on things right before I go to bed and when I get up in the morning.