DATEDIFF(날짜1, 날짜2)
TIMESTAMPDIFF(단위, 날짜1, 날짜2)
SELECT DATEDIFF('2024-01-10', '2024-01-01') AS days_difference;
SELECT TIMESTAMPDIFF(HOUR, '2024-01-01 08:00:00', '2024-01-02 11:00:00') AS hours_difference;