The IsMultiDay property returns whether the Appointment's StartDateTime and EndDateTime occur on two different dates.
With the NAS2005 Vol 1 addition of the LogicalDayOffset property, an Appointment can span across multiple logical days even when its StartDateTime and EndDateTime occur on the same actual date; in this case, the IsMultiDay property will return true.
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