This article will show you how to change the duration of a service in an appointment.
To change the duration of a service in an appointment, move your mouse to the bottom edge of the booking until your mouse changes to a down arrow, then click-and-drag the booking to increase or reduce the duration.
Or if you prefer, you can open the appointment to edit it. Click the Service booked for the appointment and the Duration on the next screen. Specify the new total amount of minutes required, click OK and Done to close and save the appointment.