def diff(self, dt=None, abs=True):
        """
        Returns the difference between two Date objects as a Period.

        :type dt: Date or None

        :param abs: Whether to return an absolute interval or not
        :type abs: bool

        :rtype: Period
        """
        if dt is None:
            dt = self.today()

        return Period(self, Date(dt.year, dt.month, dt.day), absolute=abs)
Returns the difference between two Date objects as a Period.

        :type dt: Date or None

        :param abs: Whether to return an absolute interval or not
        :type abs: bool

        :rtype: Period