Birthday
    SELECT SQL_CACHE /*??? prefira memcache, APC, etc..*/
      name,
      birthday,
      YEAR(birthday),
      YEAR(NOW()),
      (YEAR(NOW()) - YEAR(birthday)),
      DATE_ADD(birthday, INTERVAL (YEAR(NOW()) - YEAR(birthday)) YEAR),
      DATE_ADD(NOW(), INTERVAL 15 DAY )
    
    FROM customers
    
    WHERE
    
    DATE_ADD(birthday, INTERVAL (YEAR(NOW()) - YEAR(birthday)) YEAR) 
      BETWEEN 
        DATE( NOW() )
      AND 
        DATE_ADD(NOW(), INTERVAL 15 DAY )
    