Varies depending on the day and semester. The first 10 weeks is filled with traditional anatomy lecture and lab so you'll pretty much be at school all day for the most part.
Once anatomy ends and normal PBL takes over you have a 2hr PBL session on Monday, Wed, and Fridays. On Tuesdays and Thursdays is when you have other stuff like Clinical Exam lecture and lab, OMM lecture and lab, and then any "mini-course" lectures (stuff like Ethics, Public Health, etc...) So Mondays, Wed, and Fridays you usually only have to be here 2hrs for PBL, Tuesdays and Thursdays can either be short or long depending on if you have mini-course lectures, or other things on the schedule.