SQL>
SQL> SELECT TO_CHAR(SYSDATE, 'ddMONyyyy') Today,
2 TO_CHAR(ADD_MONTHS(SYSDATE, 3), 'ddMONyyyy') "+ 3 mon",
3 TO_CHAR(ADD_MONTHS(SYSDATE, -23), 'ddMONyyyy') "- 23 mon"
4 FROM dual;
TODAY + 3 mon - 23 mon
--------- --------- ---------
30AUG2006 30NOV2006 30SEP2004
SQL>
SQL>