So your weekly schedule can change depending what block/course you're in. AM is 8-12, PM is 1-5. (We're always free 12-1). But there are rarely ever 8-5PM days. I think Anatomy is the only block in M1 that was somewhat more regularly with longer days (9-4/8-5), and that's because of the lab. Lab however was not mandatory, so lab groups usually divided up the work, and went on specific days.
*Also, just to mention, even though the schedule is blocked out 8-5, sometimes it's not a hard time-line. Most things like labs get done way before the time we have until etc. If a lecture is scheduled to 5pm (pretty rare), they do usually fill the time allotted. Again, this mostly applies to Anatomy. This will change somewhat because they made some changes to the curriculum so you will have all Tuesday afternoons free starting August.
If you're someone who doesn't go to class, you will certainly have a lot of free time. If you do go to class, there's still a good amount of time scheduled out. In any given week you will have about 2 free afternoons (nothing after 12 PM). Most of the times if you do have anything after 12, they are not mandatory unless it's small group. About 1 afternoon block a week, you will either have Medical interviewing, or Physical Exam (depending on which semester you are in), which is mandatory.
Personally, I think I have more scheduled out time in Medical School than I did in undergrad.