Count between dates and operate between rows - SQL
WHERE timestamp &gt;= '2021-04-02'
  AND timestamp  &lt; '2021-04-02' + INTERVAL 1 MONTH
  AND status = &quot;done&quot;

(If you need to discuss further, please provide SHOW CREATE TABLE and more details about the desired query.)
And this index may help with performance:
INDEX(status, timestamp)