By default, the the AllowUpdateDisableZone property is False, so the user can not update or create new events in a disabled zone. The DisableZoneFormat property of the Calendar returns or sets an expression that determines the dates being disabled in the calendar/schedule panel. The AllowUpdateDisableZone property on True, lets user to update the disabled zones. The AllowCreateEvent property indicates the combination of the keys to let user creates new events. The AllowMoveEvent property indicates the combination of the keys to let user moves the events. The AllowResizeEvent property indicates the combination of the keys to let user resizes the events.

The following screen shot shows all dates as disabled ( the entire month is selected ) :

DisableZoneFormat = "1"

A disable zone, shows as grayed as in the following screen shot ( only dates: 23, 24, and 25 are enabled, and the rest are disabled, the entire month is selected ):