How long is your lunch?
A few years ago my staff had a 60 minute "lunch" because of the transition from the HS to MS schedule. The first band after our lunch was his MS Band. I asked him to make sure the band hall was set up and ready to go for his rehearsal. This included set up, stands, percussion, and having his agenda on the board. He would often leave campus, which I didn't have a problem with, and come back minutes before his rehearsal started. He would spend a good 10-15 minutes of lost instructional time getting students in their seats.