Untitled

select submission_date ,
(SELECT COUNT(distinct hacker_id)  
 FROM Submissions s2  
 WHERE s2.submission_date = s1.submission_date 
 AND (SELECT COUNT(distinct s3.submission_date) 
 FROM Submissions s3 
 WHERE s3.hacker_id = s2.hacker_id 
 AND s3.submission_date < s1.submission_date) = dateDIFF(s1.submission_date , '2016-03-01')) ,
(select hacker_id  
 from submissions s2 
 where s2.submission_date = s1.submission_date 
 group by hacker_id 
 order by count(submission_id) desc , hacker_id limit 1) as shit,
(select name from hackers where hacker_id = shit)
from (select distinct submission_date from submissions) s1
group by submission_date;