SELECT LAST_DAY(SYSDATE) FROM DUAL; -- 01/31/2020 12:34:04 SELECT TO_CHAR(LAST_DAY(SYSDATE),'DD') FROM DUAL; --31 SELECT TO_CHAR(LAST_DAY(TO_DATE('201911','YYYYMM')),'DD') FROM DUAL; --30 SELECT TO_CHAR(LAST_DAY(TO_DATE('20221110','YYYYMMDD')),'DAY') FROM DUAL; --목요일 SELECT TO_CHAR(LAST_DAY(TO_DATE('20221110','YYYYMMDD')),'DY') FROM DUAL; --목