I would like to find out what a typical day is like for a 3rd or 4th year during rotations:
What do you spend most of your day doing?
When do you get a chance to study?
What tests are you required to take during your rotations?
How long is a typical day? Do you work on the weekends?
Are you constantly being quizzed? Do you see patients on your own?
There is no typical day if you lump all rotations together into one question. People can probably answer the question as to a specific rotation, but since many have q3 or q4 call, every 3rd or 4th day will be different, and every 4th or 5th day will be post-call and again different, so it will be unlikely even within a single rotation that there will be a typical day in terms of hours.
In an in-patient medicine rotation on a non-call day you probably show up at 6, preround on your patients and check in on them and get all the overnight vitals and labs, then round with a resident or attending, then have morning report, then round with attending. Then write soap notes on your patients and do all the things the team wants done on your patients for the rest of the afternoon, perhaps broken up by an hour of didactics. Then perhaps another set of table-rounds with the attending on patients at the end of the day, and probably leave at six-ish on a good day. You may be required to stay on overnight on the long call days (depending on your hospital's system), and leave by one on the post-call days (after a 30 hour shift). In most rotations, you will work at least some weekend days. At some places you get 4 days off per month, which usually will be weekend days (but not necessarilly). You will be "pimped" by senior residents and attendings periodically. You may also be asked to put together presentations for the next morning's rounds.
You study during the down-time you may have, as well as in the evenings and whatever weekend time you have off. There is a shelf exam at the end of each core rotation, which generally accounts for some portion of your grade, and you will be working through a few review books during your "spare time" in each rotation. But much of your grade will be subjective, and based on your day to day performance and ability to wow the attendings when they ask their pimp questions or when you present your patients to them.
In surgical fields, the hours tend to be longer, and you tend to spend the bulk of your day in the OR, rather than rounding or getting stuff done on your patients.