Truncates 7:45:26 P.M. on May 25, 2005, to the hour
SQL>
SQL> --Truncates 7:45:26 P.M. on May 25, 2005, to the hour
SQL>
SQL> SELECT TO_CHAR(TRUNC(TO_DATE('25-MAY-2005 19:45:26','DD-MON-YYYY HH24:MI:SS'), 'HH24'), 'DD-MON-YYYY HH24:MI:SS') FROM dual;