Set the view limits to include the data range.

def autoscale(self):
        """
        Set the view limits to include the data range.
        """
        dmin, dmax = self.datalim_to_dt()
        if dmin > dmax:
            dmax, dmin = dmin, dmax

        # We need to cap at the endpoints of valid datetime

        # TODO(wesm): unused?

        # delta = relativedelta(dmax, dmin)
        # try:
        #     start = dmin - delta
        # except ValueError:
        #     start = _from_ordinal(1.0)

        # try:
        #     stop = dmax + delta
        # except ValueError:
        #     # The magic number!
        #     stop = _from_ordinal(3652059.9999999)

        dmin, dmax = self.datalim_to_dt()

        vmin = dates.date2num(dmin)
        vmax = dates.date2num(dmax)

        return self.nonsingular(vmin, vmax)