Exam sittings were every six months, which allowed me to take time to relax between exams and enjoy the Christmas and summer periods each year. They are flexible too, so if you wanted to take a year off exams for example, you can. As for studying, the professional modules in particular required significant study time. For most modules I attended courses with tuition providers in addition to regular home study. On average, I would try to complete a couple of hours of work per evening and half a day on weekends.