Calendar yearCalendar = new Calendar();
yearCalendar.DisplayMode = CalendarMode.Year;
yearCalendar.DisplayModeChanged +=
    new EventHandler<CalendarModeChangedEventArgs>(Calendar_DisplayModeChanged);

// root is a Panel that is defined elswhere.
root.Children.Add(yearCalendar);

private void Calendar_DisplayModeChanged(object sender,
                                         CalendarModeChangedEventArgs e)
{
    Calendar calObj = sender as Calendar;

    calObj.DisplayMode = CalendarMode.Year;
}