[oracle@lnkf ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.4.0 Production on Fri Jun 21 08:17:11 2024 Copyright (c) 1982, 2013, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> SELECT TO_DATE('2023-12-30', 'YYYY-MM-DD') + INTERVAL '1' MONTH FROM DUAL; TO_DATE('2023-12-30 ------------------- 2024-01-30 00:00:00 SQL> SELECT ADD_MONTHS(TO_DATE('2023-12-30', 'YYYY-MM-DD'), 1) FROM DUAL; ADD_MONTHS(TO_DATE( ------------------- 2024-01-30 00:00:00 SQL> SELECT ADD_MONTHS('2023-12-30', 1) FROM DUAL; ADD_MONTHS('2023-12 ------------------- 2024-01-30 00:00:00 SQL> SELECT ADD_MONTHS('2023-12-30', 1); SELECT ADD_MONTHS('2023-12-30', 1) * ERROR at line 1: ORA-00923: FROM keyword not found where expected