Found at Common Tasks > End of year procedures > Clear bookings from schedule for ALL teachers.
This script will take you to the Contacts file where you can clear the schedule for all teachers. It will pause before each teacher so you can decide to clear some schedules but keep others. Clearing the schedule keeps the timeslots but clears the bookings. It will not delete any future calendar entries for these bookings.
Note this will also clear the day/venue/time information for any ensembles/classes that the teacher is involved in.
This script may be very helpful for schools where students' lesson times are determined anew each year. It's unlikely to be used by conservatoriums, where a majority of students will retain their lesson timeslots from year to year.