def get_date_bounds(self):
        """
        Return the upper and lower bounds along
        with operators that are needed to do an 'in range' test.
        Useful for SQL commands.

        Returns
        -------
        tuple: (`str`, `date`, `str`, `date`)
                (date_gt, start, date_lt, end)
        e.g.:
                ('>=', start_date, '<', end_date)
        """
        start = end = None
        date_gt = '>='
        date_lt = '<='
        if self:
            if self.start:
                start = self.start
            if self.end:
                end = self.end
            if self.startopen:
                date_gt = '>'
            if self.endopen:
                date_lt = '<'

        return date_gt, start, date_lt, end
Return the upper and lower bounds along
        with operators that are needed to do an 'in range' test.
        Useful for SQL commands.

        Returns
        -------
        tuple: (`str`, `date`, `str`, `date`)
                (date_gt, start, date_lt, end)
        e.g.:
                ('>=', start_date, '<', end_date)