Вземете цялата Дата на месеца заедно с данните от таблицата

Между другото, не се нуждаете от присъединяването на user_profile.

Ако имате dates таблица със съответните дати, това е доста лесно:

SELECT dates.day AS `Date`, COUNT(DISTINCT ts.user_id) AS user_count
FROM dates
LEFT OUTER JOIN tracked_search AS ts
    ON ts.created = dates.day
GROUP BY dates.day;

Тъй като вероятно нямате dates таблица и може да не искате да създадете и поддържате такава, можете да използвате едно от решенията за генериране на списък с дати в движение. напр. Вземете списък с дати между две дати или Как да получите списък с дати между две дати в заявката за избор на mysql

SELECT dates.day AS `Date`, COUNT(DISTINCT ts.user_id) AS user_count
FROM (
    SELECT ADDDATE('1970-01-01', t4.i * 10000 + t3.i * 1000 + t2.i * 100 + t1.i * 10 + t0.i) AS day
    FROM (SELECT 0 AS i UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS t0,
         (SELECT 0 AS i UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS t1,
         (SELECT 0 AS i UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS t2,
         (SELECT 0 AS i UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS t3,
         (SELECT 0 AS i UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS t4
) AS dates
LEFT OUTER JOIN tracked_search AS ts
    ON ts.created = dates.day
WHERE dates.day >= '2017-10-01'
AND dates.day < '2017-11-01'
GROUP BY dates.day;