I have set my business hours as starting at 8 and ending at 19. With the height spec set to Business Hours the Calendar only displays from 9 to 19. When I change the ScrollPositionHour value to 8 in the GUI and hit return or click out of the box it reverts to 9. The only way I can change this is to set the business hours start value to 7 (or any other value), set the ScrollPositionHour to 8, and then change the business hours start value back to 8. This is probably caused by the fact that the Calendar simply refuses, with the Business Hours height spec, to display more than ten business hours. I can have it display from 9 to 19 or from 8 to 18 but not from 8 to 19, which is what I actually want.