ClinicOffice allows you to decide whether to show or hide cancelled appointments. Most of the time, it’s usually best to hide cancelled appointments because when you’re scanning through the diary to find a free slot, having cancelled appointments visible can confuse matters. At other times however, you may want to include cancelled appointments in the diary so that you can get a visual representation of how many patients have cancelled.
To show or hide cancelled appointments :-
 Click the Diary Options button (top right above the diary)  On the “Appointment Options” tab notice the “Show cancelled appointments” tick box  Simply tick or untick this box and click OK