When the CalendarItem represents an item in the MinCalendarMode, the value of this property is based on whether the date that the item represents has been selected. When in navigation mode, this value is based on whether the item is active since selection can only be modified in the user interface when the CurrentMode equals the MinCalendarMode.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2