Use the DataChanging property event to increase or decrease the browsed date as user clicks the arrows in the header of the CalendarCombo. The Date property specifies the browsed date. The DateChanged event notifies your application that the browsed date is changed. By default, the Cancel parameter is False, so the default operation is executed when the user clicks a button in the header of the CalendarCombo. The SelDate property indicates the date being selected.

The following VB sample changes the month to prev or next when user clicks the LEFT or RIGHT buttons, instead prev / next Year ( which is by default ).

Private Sub CalendarCombo1_DateChanging(ByVal HeaderArrow As EXCalendarComboLibCtl.HeaderArrowEnum, Cancel As Variant)
    Cancel = True
    With CalendarCombo1
        If (HeaderArrow = exPrevYear) Then
            .Date = DateAdd("m", -1, .Date)
        Else
            If (HeaderArrow = exNextYear) Then
                .Date = DateAdd("m", 1, .Date)
            End If
        End If
    End With
End Sub

Previously the ShowMonthSelector property is set on False, so only the LEFT and RIGHT buttons are displayed. By default, the LEFT and RIGHT arrows changes the year, while the UP and DOWN arrows changes the month. The sample hides the UP and DOWN buttons, and let only the LEFT and RIGHT buttons and the code changes the current date to prev or next month.