BCGSuite for MFC
BOOL CBCGPCalendar::SetSelectedDates ( const CList< DATE, DATE & > &  lstDates,
BOOL  bNotify = TRUE,
BOOL  bRedraw = TRUE 

Selects multiple dates

Use this method to select multiple dates. If bNotify is TRUE, the calendar calls OnSelectionChanged() (which in turn sends out a notification message BCGM_CALENDAR_ON_SELCHANGED).

lstDatesContains the list of dates to select.
bNotifyIf TRUE, the calendar sends "selection changed" notification.
bRedrawIf TRUE, the calendar will be redrawn to reflect the new selection state.