ROUND(date_in_1,'CC') : ROUND « Date Timestamp Functions « Oracle PL/SQL Tutorial

SQL>
SQL> DECLARE
  2     date_in_1 DATE := TO_DATE('24-Feb-2002','DD-MON-YYYY');
  3     date_in_2 DATE := TO_DATE('24-Feb-1902','DD-MON-YYYY');
  4     date_in_3 DATE := TO_DATE('24-Feb-2002 05:36:00 PM','DD-MON-YYYY HH:MI:SS AM');
  5
  6     round_1 DATE;
  7     round_2 DATE;
  8     round_3 DATE;
  9
 10  BEGIN
 11     round_1 := ROUND(date_in_1,'CC');
 12     round_2 := ROUND(date_in_2,'CC');
 13     round_3 := ROUND(date_in_3,'HH');
 14
 15     DBMS_OUTPUT.PUT_LINE(TO_CHAR(round_1,'DD-MON-YYYY HH:MI:SS AM'));
 16     DBMS_OUTPUT.PUT_LINE(TO_CHAR(round_2,'DD-MON-YYYY HH:MI:SS AM'));
 17     DBMS_OUTPUT.PUT_LINE(TO_CHAR(round_3,'DD-MON-YYYY HH:MI:SS AM'));
 18  END;
 19  /

PL/SQL procedure successfully completed.

SQL>

13.15.ROUND
	13.15.1.	The ROUND Function
	13.15.2.	Datetime Formatting Parameters for ROUND(x[, unit])
	13.15.3.	ROUND(x[, unit]) : round x. By default, x is rounded to the beginning of the nearest day
	13.15.4.	Round date to day
	13.15.5.	Rounds May 25, 2005, to the first day in the nearest month
	13.15.6.	Rounding to the Nearest Minute
	13.15.7.	ROUND(date_in_1,'CC')
	13.15.8.	Round result from months_between