SELECT
     CALENDAR.REGIST_DATE AS REGIST_DATE
    ,substr('日月火水木金土', strftime("%w", CALENDAR.REGIST_DATE, 'localtime')+1, 1) AS WK
    ,COUNT(USERS.USER_CODE) AS TOTAL
FROM
(
          SELECT DATE('2022-08-01') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-02') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-03') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-04') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-05') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-06') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-07') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-08') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-09') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-10') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-11') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-12') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-13') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-14') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-15') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-16') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-17') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-18') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-19') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-20') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-21') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-22') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-23') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-24') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-25') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-26') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-27') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-28') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-29') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-30') AS REGIST_DATE
UNION ALL SELECT DATE('2022-08-31') AS REGIST_DATE
) AS CALENDAR
LEFT OUTER JOIN USERS
 ON CALENDAR.REGIST_DATE = strftime('%Y-%m-%d', USERS.CONFIRMED_AT)
GROUP BY CALENDAR.REGIST_DATE