NLS_CALENDAR

Property	Description
Parameter type	String
Syntax	`NLS_CALENDAR = "calendar_system"`
Default value	None
Modifiable	`ALTER SESSION`
Range of values	Any valid calendar format name
Basic	No

NLS_CALENDAR specifies which calendar system Oracle uses. It can have one of the following values:

Arabic Hijrah
English Hijrah
Gregorian
Japanese Imperial
Persian
ROC Official (Republic of China)
Thai Buddha

For example, suppose NLS_CALENDAR is set to "Japanese Imperial", the date format is "E YY-MM-DD". ("E" is the date format element for the abbreviated era name.) If the date is May 15, 1997, then the SYSDATE is displayed as follows:

SELECT SYSDATE FROM DUAL;
SYSDATE
--------
H 09-05-15