Return next five birthdays from user's date of birth

gistfile1.sql

SELECT first_name, last_name, dob, DATEDIFF(next_birthday, NOW()) AS distance 
  FROM (
    SELECT *, ADDDATE(birthday, INTERVAL birthday < DATE(NOW()) YEAR) AS next_birthday
    FROM (
      SELECT *, ADDDATE(dob, INTERVAL YEAR(NOW()) - YEAR(dob) YEAR) AS birthday
      FROM users
      WHERE active = 1 AND dob IS NOT NULL
    ) AS T1
  ) AS T2
ORDER BY distance ASC
LIMIT 5