When the AutoAddAdditionalInterval property returns true, a weekly interval automatically appears above the primary interval so that the days of each week are grouped. This interval is not added to the AdditionalIntervals, but does appear in the VisibleIntervals collection.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, 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