How to check if a particular date is a working date

-- identify the calendar code
SELECT organization_code,
       calendar_code,
       negative_inv_receipt_code,
       stock_locator_control_code,
       organization_id
  FROM mtl_parameters
 WHERE organization_code = '313'

-- check if it is a working day time
 SELECT 1
  FROM  bom_calendars cal,
        bom_shift_dates sd,
        bom_shift_times st
  WHERE cal.calendar_code = 'GIL_FC_CMO'--c_calendar_code
  AND sd.calendar_code = cal.calendar_code
  AND st.calendar_code = sd.calendar_code
  AND sd.shift_num = st.shift_num
  -- B4610901, Rajesh Patangya 15-Sep-2005
  AND (sd.shift_date + (st.from_time/86400)) <= '30-JAN-2015'
  AND DECODE(
        SIGN(st.from_time - st.to_time),
    1,(sd.shift_date+1), sd.shift_date
         ) + (st.to_time/86400) >=  '30-JAN-2015'
  AND sd.seq_num IS NOT NULL