Go to Settings / Service Providers / Schedules or Stand-Alone Resources / Schedules and modify the schedules as necessary.  If there are bookings during that time, you will have the option to “Continue Without Canceling 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”.