I am paid hourly, and work university term time (30 wks) of the year, approx 24 hours a week in the UK. As others have said, being paid hourly might be better in terms of being clear when you're working and when you're not as long as you will be paid for the same things other contract staff would be paid for. My holiday pay is added to my hourly rate. I love working part time, it definitely helps with increasing job satisfaction.