A SQL (MySQL) function that returns the number of the quadrimester based on the date

gistfile1.sql

DELIMITER //

CREATE FUNCTION QUADRIMESTER (date_and_time DATETIME)
  RETURNS INT(1)
  BEGIN
    DECLARE month_of_the_year INT(1);

    SET month_of_the_year = MONTH(date_and_time);

    IF month_of_the_year >= 1 AND month_of_the_year <= 4 THEN RETURN 1;
    ELSE
      IF month_of_the_year >= 5 AND month_of_the_year <= 8 THEN RETURN 2;
      ELSE RETURN 3;
      END IF;
    END IF;
  END //

DELIMITER ;

SELECT IF(QUADRIMESTER('2010-01-01') = 1, "PASS", "FAIL") "2010-01-01 == 1";
SELECT IF(QUADRIMESTER('2010-04-30') = 1, "PASS", "FAIL") "2010-04-30 == 1";
SELECT IF(QUADRIMESTER('2010-06-30') = 2, "PASS", "FAIL") "2010-06-30 == 2";
SELECT IF(QUADRIMESTER('2010-08-31') = 2, "PASS", "FAIL") "2010-08-31 == 2";
SELECT IF(QUADRIMESTER('2010-09-01') = 3, "PASS", "FAIL") "2010-09-01 == 3";
SELECT IF(QUADRIMESTER('2010-12-31') = 3, "PASS", "FAIL") "2010-12-31 == 3";