You can cancel any appointments using the Appointment Calendar so that the system will update all relevant records, such as Contact Schedule Item for Students and Staff, as well as the Organization Event record:
A notification email will be sent if you configured an Email to fire for a cancellation. We recommend that the Email includes options for rescheduling.
There is a cancellation template in each user's profile in the Appointment Calendar. Each user should set this up:
The Cancelled Appointment will change color on the Appointment Calendar, indicating the appointment is now canceled and not active: