How to exclude fridays(holiday) in sql query

Hi

I have a query where i need to exclude fridays( Holiday) in a month to run the data..Ex: I have a date parameter and sale value. So need to get the value based on sale for the day from the selected date parameter. Can anyone help me how to exclude fridays in this query as per the date paremeter .

select 'Sales For The Day' Particulars, a.*  from (

select *  from

(

SELECT

  IOD.ORGANIZATION_CODE ORGANIZATION_CODE,

  SUM (

  CASE

    WHEN RCTT.TYPE = 'INV'

    THEN (RCTL.EXTENDED_AMOUNT * NVL (RCT.EXCHANGE_RATE, 1))

    WHEN RCTT.TYPE = 'DM'

    THEN (RCTL.EXTENDED_AMOUNT * NVL (RCT.EXCHANGE_RATE, 1))