For each location, you can specify the default length for scheduling appointments. The appointment length can be changed as needed on an appointment-by-appointment basis.
To change the default appointment length
If you are not already viewing the correct location, select it on the Location menu.
On the Settings menu, under Location, click (or tap) Location Hours.
The Location Hours page opens and displays an overview of the weekly schedule.
Enter the desired Default appointment length in minutes. (Also, you can select a length from the list that appears when you click in, or tap, the box.)
Click (or tap) the Set link. This link is available only if you have changed the Default appointment length.
The change affects all appointments that are made in the current location from now on.