CalendarView.DayStartHour
From Jeremie Leroy - XOJO Controls Wiki
Property (As Single)
If this property is different than 0.0, the hours from midnight to DayStartHour will be darkened. The default value is 6.0
Example
This example sets the DayStartHour to 8 AM. <rbcode> me.DayStartHour=8.0 </rbcode>