About

NLS_DATE_LANGUAGE is a parameter which control the language used in the date format datatype and that you can use to control the implicit datatype conversion

Example

SQL> alter session set NLS_DATE_LANGUAGE = "AMERICAN";

Sessie is gewijzigd.

SQL> select TO_DATE('01-OCT-2010','DD-MON-YYYY') from dual;

TO_DATE(
--------
01-10-10

SQL> alter session set NLS_DATE_LANGUAGE = "DUTCH";

Sessie is gewijzigd.

SQL> select TO_DATE('01-OCT-2010','DD-MON-YYYY') from dual;
select TO_DATE('01-OCT-2010','DD-MON-YYYY') from dual
               *
FOUT in regel 1:
.ORA-01843: Geen geldige maand.


SQL> select TO_DATE('01-OKT-2010','DD-MON-YYYY') from dual;

TO_DATE(
--------
01-10-10