SELECT ID, TO_CHAR(Start_Date, 'DY') AS "DY", TO_CHAR(Start_Date, 'Dy') AS "Dy"  FROM Employee;

SELECT BUS_DT, TO_CHAR (BUS_DT, 'DY'), COUNT(*) 
FROM <TABLENAME> 
WHERE BUS_DT > '01-JUN-2017' AND TO_CHAR (BUS_DT, 'DY') = 'SAT'
GROUP BY BUS_DT,  TO_CHAR (BUS_DT, 'DY')
ORDER BY BUS_DT

TO_CHAR (my_date, 'DY', 'NLS_DATE_LANGUAGE=ENGLISH') IN ('SAT', 'SUN')

SELECT TO_CHAR(SYSDATE,'DY') FROM DUAL;

TO_CHAR(TO_DATE(BUS_DT,'DD-MON-YYYY'),'DY');