-- https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/Data-Types.html
SELECT TO_DATE('31-AUG-2004','DD-MON-YYYY') + TO_YMINTERVAL('0-1')
  FROM DUAL;
SELECT TO_DATE('29-FEB-2004','DD-MON-YYYY') + TO_YMINTERVAL('1-0')
  FROM DUAL;