How to Get Day Names in Oracle

Problem

You want to extract the name of the day of the week from a date in Oracle.

Solution 1

To extract the day name from the date, use the TO_CHAR() function. The first parameter is the date and the second is the format in which we want to output the date. To extract the day name, the format should be 'Day':

SELECT 
  TO_CHAR(DATE '2022-01-01', 'Day') 
FROM DUAL;

The result is Saturday.

Discussion

This is not the only format you can use to extract day names. Here are several alternatives:

• 'DAY' would return SATURDAY
• 'day' would return saturday
• 'DY' would return SAT
• 'Dy' would return Sat
• 'dy' would return sat
• 'D' would return 7 (based on the range 1-7, from Sunday to Saturday)

You can also extract the day name in another language. To do this, you need to use the third parameter, NLS_DATE_LANGUAGE. This parameter can take any valid language name; you can find more on this in NLS_DATE_LANGUAGE’s entry in the Oracle documentation. Let’s try an example.

Solution 2

Let’s extract the day name in German.

SELECT 
  TO_CHAR(DATE '2022-01-01', 'Day', 'NLS_DATE_LANGUAGE = German') 
FROM DUAL;

The result is Samstag.