Contracted to work 40, work about 45, but I get paid extra for every hour I do, plus I get flextime so I can take time off with my extra hours. i.e. If I do 8 extra hours in a month I can take 1 flexday or get paid for the 8 hours. If I do 12 hours in a month I can take 1 flexday and get paid for the extra 4 hours.
Its a very good system. We can start between 7-9am with lunch being from 12-2 (30mins minimum break required) and we can leave at 4pm and 3:30pm on fridays. We have to be at our desk/working between 9-12 and 2-4. We use a swipe system too for all of our timekeepings.
Also get double time on weekends and bank hols.