docs: def date_tuple(ovls):
      """
      We should have a list of overlays from which to extract day month
      year.
      """
  
      day = month = year = 0
      for o in ovls:
          if 'day' in o.props:
              day = o.value
  
          if 'month' in o.props:
              month = o.value
  
          if 'year' in o.props:
              year = o.value
  
          if 'date' in o.props:
              day, month, year = [(o or n) for o, n in zip((day, month,
                                                            year), o.value)]
  
      return (day, month, year)