day2.save(conn)
day3.save(conn)
self.assertEqual(Day.all(conn), [day1, day2, day3])
+ self.assertEqual(Day.all(conn, ('', '')), [day1, day2, day3])
self.assertEqual(Day.all(conn, ('2024-01-01', '2024-01-03')),
[day1, day2, day3])
self.assertEqual(Day.all(conn, ('2024-01-02', '2024-01-03')),