Many School systems have a 36 week school year.

With five one hour classes or rehearsals each school week, that means you have a total of approximately 180 hours per class available during the school year.

If you teach three classes, that adds up to 540 rehearsal hours for the 36 week school year.

If your rehearsals and or classes begin, on average, five minutes late, you lose a total of 45 hours of teaching time each school year.

that translates to almost two full 24 hour days of rehearsal time lost to tardiness.

If you have 40 students in each ensemble or class, and if rehearsal for your three classes begin an average of five minutes late, that calculates to a staggering loss of 1800 hours of student learning time per year.