Using the calendar, you can define new time slots by clicking and dragging, or change the duration of time slots by resizing or moving intervals.
Select the Calendar View tab, which is the default.
To create a new time slot, click an empty place in the calendar where the time slot begins. Then drag down to extend duration, releasing the mouse button when finished.
To shorten a time slot, drag its handle upward to decrease the duration of time.
To increase a time slot, drag its handle downward to increase the duration of time.
To reposition a time slot, click inside its borders and drag it to a new position.