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ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
SELECT TRUNC( SYSDATE - 1 ) + INTERVAL '8:12:34' HOUR TO SECOND
FROM DUAL;
| TRUNC(SYSDATE-1)+INTERVAL'8:12:34'HOURTOSECOND |
|---|
| 2020-06-08 08:12:34 |