def get_locator(self, dmin, dmax):
        'Pick the best locator based on a distance.'
        _check_implicitly_registered()
        delta = relativedelta(dmax, dmin)

        num_days = (delta.years * 12.0 + delta.months) * 31.0 + delta.days
        num_sec = (delta.hours * 60.0 + delta.minutes) * 60.0 + delta.seconds
        tot_sec = num_days * 86400. + num_sec

        if abs(tot_sec) < self.minticks:
            self._freq = -1
            locator = MilliSecondLocator(self.tz)
            locator.set_axis(self.axis)

            locator.set_view_interval(*self.axis.get_view_interval())
            locator.set_data_interval(*self.axis.get_data_interval())
            return locator

        return dates.AutoDateLocator.get_locator(self, dmin, dmax)
Pick the best locator based on a distance.