Intensive English sessions have 33 days of in-class instruction.  That generally makes sessions six-and-a-half weeks long, although the schedule can change due to scheduled holidays.  You can see the current calendar by clicking here.  Classes meet for four hours a day, five days a week, in the mornings.  Sometimes, the schedule changes in the summer.  The laboratory is open every class-day afternoon except after parties and field trips or on repair days.