Describes built-in month calendar control listener. If you specify listener derived from this interface to the MonthCalendar built-in control, you will be able to get notifications about new date activation.

You can find more information in comments below. Overrided methods can be found in corresponding base interface.

class IBuiltInMonthCalendarListener :public virtual IBuiltInControlListener
    {
    public:
        virtual void NotifyOnChange(IBuiltInControl *sender) = 0; // Notification called when new date becomes active
    };