With the course LECOM offers, you can use an elective rotation (grade based on your COMLEX score) or your vacation (no grade reported.) Clinical education requires you to study for sixty-hours/week. You have to turn logs in every week detailing when specifically you studied, and the studying has to be completed at LECOM or Coffee Culture (or at least last year we were allowed to use Coffee Culture, which was nice cause no dress clothes. Attire is still professional 7A-5P during the summer...) Four mornings every week there are Q-groups where you go through sample board questions. These weren't very helpful IMO. We took to extra shelf exams, I think pathology and pharmacology--these were an absolute waste of time, and we had to pay for them. Depending on when your COMLEX is scheduled, you take a COMSAE the last week or second to last week of the timeslot. If you score less than a 450, you're pulled off your second rotation and forced to study sixty-hours/week for the next entire rotation, at the end of which you repeat the COMSAE (you also go off schedule, not ideal--this continues until they determine you're capable of passing the COMLEX.)
In all honesty, if you feel you need those four-weeks to study and have vacation or an elective first (where you can schedule an easy rotation.) I recommend you do that and study on your own. Use DIT and/or UWorld questions and you'll do fine. If you still want to take it (or have to take it), use an elective for a grade. Even if you just barely pass the COMLEX, you'll get a C, but nobody cares about clinical grades really. You're going to want your vacation! Trust me on that. You'll get burnt out on rotations otherwise.
Oh, and for Christmas you get December 24-26 off (if one or more of those days falls on a weekend, your loss. If it's a tuesday to thursday like this upcoming year, you're still expected at your rotation monday and friday. It blows.) Thanksgiving you get thursday and friday off only. Those are the only holidays you get off during years three and four. (Unless your attending takes time off and lets you as well, some will push you onto other physicians though.)