I play one season per rotation. (so like spring first, then summer, etc) for uni I do a whole school year since it usually rounds out to about 6 days for me (and a season is about 5 days) I find it best since anyone new that ages up to uni would start fresh on a new "school year" and be in line with everyone else. It bothers me when the times don't match up and some people are taking finals while others are not. (i also like to keep all the sims in one dorm building unless they want to move into a greek house)