code: def max(self, axis=None, skipna=True, *args, **kwargs):
          
          nv.validate_max(args, kwargs)
          nv.validate_minmax_axis(axis)
  
          if not len(self):
              return self._na_value
  
          i8 = self.asi8
          try:
              # quick check
              if len(i8) and self.is_monotonic:
                  if i8[-1] != iNaT:
                      return self._box_func(i8[-1])
  
              if self.hasnans:
                  if skipna:
                      max_stamp = self[~self._isnan].asi8.max()
                  else:
                      return self._na_value
              else:
                  max_stamp = i8.max()
              return self._box_func(max_stamp)
          except ValueError:
              return self._na_value
docs: Return the maximum value of the Index or maximum along
          an axis.
  
          See Also
          --------
          numpy.ndarray.max
          Series.max : Return the maximum value in a Series.