Am I the only future part-timer who is finding it hard to figure out generally the nights/time range I will be in class?

The admissions board says Mon-Thurs, but the Spring schedule (and the schedule for last fall) shows part-timers in class only three nights/week. Does anyone know what the standard hours are for part-time students in the summer? I'm thinking that since the term is shorter in the summer, we'll probably be there four nights/week, but I can't tell. Thanks.