code: def _get_format_timedelta64(values, nat_rep='NaT', box=False):
      
  
      values_int = values.astype(np.int64)
  
      consider_values = values_int != iNaT
  
      one_day_nanos = (86400 * 1e9)
      even_days = np.logical_and(consider_values,
                                 values_int % one_day_nanos != 0).sum() == 0
      all_sub_day = np.logical_and(
          consider_values, np.abs(values_int) >= one_day_nanos).sum() == 0
  
      if even_days:
          format = None
      elif all_sub_day:
          format = 'sub_day'
      else:
          format = 'long'
  
      def _formatter(x):
          if x is None or (is_scalar(x) and isna(x)):
              return nat_rep
  
          if not isinstance(x, Timedelta):
              x = Timedelta(x)
          result = x._repr_base(format=format)
          if box:
              result = "'{res}'".format(res=result)
          return result
  
      return _formatter
docs: Return a formatter function for a range of timedeltas.
      These will all have the same format argument
  
      If box, then show the return in quotes