Calculating Working Days Between Two Dates

The following code, or variation thereof, was originally provided by ACL in their magazine Take Command.

DEFINE FIELD f_working_Days COMPUTED

-999 IF end_date < start_date
ROUND((end_date – start_date) / 7.00) * 5  IF (DOW(end_date) = 7 OR DOW(end_date) = 1) AND (DOW(start_date) = 7 OR DOW(start_date) = 1)
INT((end_date – start_date) / 7.00) * 5 + 7 - DOW(start_date) IF DOW(end_date) = 7 OR DOW(end_date) = 1 Value 3: INT((end_date – start_date) / 7.00) * 5 + 7 - DOW(start_date)
INT((end_date – start_date) / 7.00) * 5 + DOW(end_date) – 1 IF DOW(start_date) = 7 OR DOW(start_date) = 1
INT((end_date – start_date) / 7.00) * 5 + DOW(end_date) - DOW(start_date) + 6 IF DOW(end_date) < DOW(start_date)
INT((end_date – start_date) / 7.00) * 5 + DOW(end_date) - DOW(start_date) + 1 IF DOW(end_date) > DOW(start_date)
INT((end_date – start_date) / 7.00) * 5 + 1