-- Listing 1



DECLARE

   l_today_date        DATE := SYSDATE;

   l_today_timestamp   TIMESTAMP := SYSTIMESTAMP;

   l_today_timetzone   TIMESTAMP WITH TIME ZONE := SYSTIMESTAMP;

   l_interval1         INTERVAL YEAR (4) TO MONTH := '2011-11';

   l_interval2         INTERVAL DAY (2) TO SECOND := '15 00:30:44';

BEGIN

   NULL;

END;





-- Listing 2



BEGIN

  DBMS_OUTPUT.put_line (SYSDATE);

  DBMS_OUTPUT.put_line (SYSTIMESTAMP);

  DBMS_OUTPUT.put_line (SYSDATE - SYSTIMESTAMP);

END;

/



-- Listing 3



BEGIN

   DBMS_OUTPUT.put_line (

      ADD_MONTHS (TO_DATE ('31-jan-2011', 'dd-mon-yyyy'), 1));

   DBMS_OUTPUT.put_line (

      ADD_MONTHS (TO_DATE ('27-feb-2011', 'dd-mon-yyyy'), -1));

   DBMS_OUTPUT.put_line (

      ADD_MONTHS (TO_DATE ('28-feb-2011', 'dd-mon-yyyy'), -1));

END;