BCGControlBar Pro for MFC
void CBCGPPlannerManagerCtrl::UpdateCalendarsState ( CBCGPCalendar pWndCalendar = NULL,
BOOL  bRedraw = TRUE 

Updates state of a calendar (date picker) control.

Use this function to update state of the specified calendar (date picker) control. If pWndCalendar is NULL, this method updates state of the default calendar associated with the Planner control. The default calendar control is assigned by SetCalendar().

pWndCalendarPoints to a calendar, whose state should be updated.
bRedrawIf TRUE, the control will be redrawn.