NLS_CALENDAR

NLS_CALENDAR specifies which calendar system Oracle uses.

Property	Description
Parameter type	String
Syntax	NLS_CALENDAR = "calendar_system"
Default value	None, implies GREGORIAN
Modifiable	ALTER SESSION
Modifiable in a PDB	Yes
Range of values	Any valid calendar format name
Basic	No

NLS_CALENDAR can have one of the following values:

• Arabic Hijrah

• English Hijrah

• Ethiopian

• GREGORIAN

• Japanese Imperial

• Persian

• ROC Official (Republic of China)

• Thai Buddha

For example, suppose NLS_CALENDAR is set to English Hijrah. The date format is DD Month YYYY. If the date is March 7, 2025, then the SYSDATE is displayed as follows:

SELECT SYSDATE FROM DUAL;
SYSDATE
--------------------------
07 Ramadan            1446

Note: The value of the initialization parameter NLS_CALENDER is used to initialize the session value of this parameter, which is the actual value referenced by the SQL query processing. If the initialization parameter is not specified, the initial session value becomes GREGORIAN. This initial value is overridden by a client-side value if the client is OCI-based and the NLS_LANG client setting (environment variable) is defined.

See Also: Oracle AI Database Globalization Support Guide for a listing of available calendar systems