docs: def date_time(name=None):
      """
      Creates the grammar for a date and time field, which is a combination of
      the Date (D) and Time or Duration field (T).
  
      This field requires first a Date, and then a Time, without any space in
      between.
  
      :param name: name for the field
      :return: grammar for a Date and Time field
      """
      if name is None:
          name = 'Date and Time Field'
  
      date = basic.date('Date')
      time = basic.time('Time')
  
      date = date.setResultsName('date')
      time = time.setResultsName('time')
  
      field = pp.Group(date + time)
  
      field.setParseAction(lambda d: _combine_date_time(d[0]))
  
      field.setName(name)
  
      return field.setResultsName('date_time')