By default when a date is brought into view the XamMonthCalendar will ensure that the ReferenceDate, and therefore the dates displayed by the groups in the control, is such that the first group contains the MinDate or a date after that and the last group contains the MaxDate or a date before that - i.e. it attempts to avoid having groups without items. However there are cases where months should be given less priority and allowed to be empty such as when showing a small preview of the previous and/or next month. When IsLeadingGroup or IsTrailingGroup is set to true, the XamMonthCalendar will ignore these groups when adjusting/calculating the reference date and therefore these groups may be empty.
Note: This property is always false for groups created by the CalendarItemGroupPanel. It is intended to be used when creating a custom XamMonthCalendar template.
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