Calculate an expected delivery date (accounting for holidays) in business days using JavaScript?

Question

After revisiting this script, and some modifications, the following is available to allow a user to add a feature that calculates the expected delivery date.

Answer 1

Change line 7 from

ship.setDate( safety );  // add a number of days

to

ship.setDate( ship.getDate() + safety );

The problem was that you want to add days, not set days.