I'm a third year who has 3 weeks and a few days left until fourth year. The rotation I am on now is Peds, and since I am typing on SDN at around 10 am, that tells you how laid back it is! As 2nd (well, now 4th 😉 )year said, your experience really will depend on which type of hospital you are at, teaching vs. nonteaching, etc.
Here have been my experiences so far.
Psych/Neuro - my first rotation. Was an easy rotation to start off with. I would get to the clinic (I ended up doing outpatient psych) around 8:00 and would be done by 3:00. And this was MWF. T/Th I didn't have to go because no patients came to the clinic. It was a good way to ease myself into rotations. For neuro I would get to the hospital around 7:30 and go to morning report, then see patients. Was also pretty laid-back, but the attendings rounded in the afternoon and that kind of sucked.
FP - I did FP with a DO in his office - and I loved it. I want to go into FP, and I like the outpatient experience more than the hospital stuff. Hours were 9-5.
Medicine - I did my rotation at a non-teaching hospital, so I kind of got shuffled around from attending to attending. Make sure you know everything about your patient - any medication changes, significant past medical history, etc. Hours varied depending on the attending, but usually I was there from 8-5 or so.
Surgery - I was terrified of surgery at first, but I ended up kind of liking it. This is the rotation that the hours suck for though - getting to the hospital at 5:30 am and not leaving until around 5 or 5:30 pm. I did the rotation in December-January, so I hated going to the hospital when it was dark and leaving when it was dark. At least you won't have that problem doing surgery in the summer! Make sure you have comfortable shoes! And make sure you ask the cardinal questions: any BM, flatus, if they are using their incentive spirometer, tolerating diet...
Ob/Gyn - I thought I would hate Ob/Gyn, but I actually liked it too. I think your experience will vary depending on if you are male or female. The male students I have talked to don't necessarily get to do as many paps, pelvics, etc. as a female student does. I am a female so I got to do a lot. My rotation consisted of outpatient, OR, and L&D duties, as well as writing notes on post-op and postpartum patients. Usually hours were from 6:30-4:30.
Peds - last rotation! Great one to end the third year with (as I am quickly losing motivation). I get here at 7 and am done by 4 or 4:30.
Whew, I think this is the longest post I have ever typed. Hope it helped! 🙂