ret = Day.by_date_range_with_limits(self.conn, (start, end), 'id')
days, start, end = ret
days = Day.with_filled_gaps(days, start, end)
ret = Day.by_date_range_with_limits(self.conn, (start, end), 'id')
days, start, end = ret
days = Day.with_filled_gaps(days, start, end)