Property Description
Parameter type String
Syntax NLS_TIMESTAMP_FORMAT = "format"
Default value Derived from NLS_TERRITORY
Range of values Any valid datetime format mask

NLS_TIMESTAMP_FORMAT defines the default timestamp format to use with the TO_CHAR and TO_TIMESTAMP functions.

The value must be surrounded by quotation marks as follows:


You can specify the value of NLS_TIMESTAMP_FORMAT by setting it in the initialization parameter file. You can specify its value for a client as a client environment variable.

You can also alter the value of NLS_TIMESTAMP_FORMAT by changing its value in the initialization parameter and then restarting the instance. To alter the value during a session use the ALTER SESSION SET statement.


The value of this initialization parameter NLS_TIMESTAMP_FORMAT is used to initialize the session value of this parameter, which is the actual value referenced by the SQL query processing. This initial value is overridden by a client-side value if the client uses the Oracle JDBC driver or if the client is OCI-based and the NLS_LANG client setting (environment variable) is defined. The initialization parameter value is, therefore, usually ignored.