See: http://docs.activestate.com/activetcl/8.5/tklib/widget/widget_calendar.html

'''Questions/Remarks'''

   * Is it possible to "drive" this widget without using a mouse? I didn't find any key bindungs...
   * Did a few tests with '''-textvariable'''. The coupling didn't seem to work (changes in the var are not reflected and vice versa)...?