Go to Settings / Service Providers / Schedules or Resources / Schedules and modify each schedule as necessary.  If there are bookings during that time, you will have the option to “Continue Without Cancelling Appointments” or “Cancel All of the Appointments” for that period.  Canceling All of the Appts for that period is called the Bump feature. You can print a list of affected appointments by selecting “View Appointments Before Canceling”.