Setting up an override for an event is when you add a duration time to an event that is different from the default duration time.
Note: A duration time override for a resource cannot be less than the practice
Default Time Interval, which is set on the Appt Scheduling Practice Preferences.
For example, if the default time interval is 30 minutes, then you cannot set a resource duration time override for less than 30 minutes. However, if the default time interval changes, the duration time for the appointment reflects the default time interval, not the resource duration time override.