Returns an integer between 1 and 7 which represents the day of the week, where 1 is Sunday and 7 is Saturday. The argument must be a date or a timestamp.
Example:
Using the EMPLOYEE table, return the day of the week that Christine Haas (EMPNO='000010') started (HIREDATE).
SELECT DAYOFWEEK(HIREDATE) FROM EMPLOYEE WHERE EMPNO = '000010'
Returns 6 when using the sample table.