WITH t AS(
SELECT
    MEMBER_CODE
    ,MIN(SUBSTR(LOGIN_DATETIME,1,10)) AS FIRST_LOGIN
FROM
    ACCESS_LOG
WHERE SUBSTR(LOGIN_DATETIME,1,7) = '2023-08'
GROUP BY 1
)

SELECT
    FIRST_LOGIN
    ,COUNT(MEMBER_CODE) AS MEMBER_CNT
FROM t
GROUP BY FIRST_LOGIN
ORDER BY FIRST_LOGIN DESC