The Interval property returns or sets the length of a time slot in minutes. Read/write.
objCalendarView.Interval
Long
The Interval property is forced by the CDO Rendering Library to a value between 5 and 60 that divides integrally into 60. The possible resulting values are 5, 6, 10, 12, 15, 20, 30, and 60. The default value of Interval is 30 minutes.
The Interval property applies only when the Mode property of the calendar view contains CdoModeCalendarDaily. If Mode is CdoModeCalendarWeekly, time slots are not displayed, and each AppointmentItem object is rendered with its StartTime and EndTime values.