Try to convert axes.

def _convert_axes(self):
        """
        Try to convert axes.
        """
        for axis in self.obj._AXIS_NUMBERS.keys():
            new_axis, result = self._try_convert_data(
                axis, self.obj._get_axis(axis), use_dtypes=False,
                convert_dates=True)
            if result:
                setattr(self.obj, axis, new_axis)