Calculating Due Date Based on Requested Date

I've been reviewing the Using DurationCalculator To Calculate a Due Date - ServiceNow Wiki wiki article to figure out how to set the default for a Catalog variable 'Due Date' to three business days from the 'Requested Date' = javascript:gs.now(). I think I need to create a schedule to incorporate in the scripting that is provided in the wiki article but I'm not sure how to design one that defaults to three weekdays from now. I'm still not too comfortable with scripting to but I think that is what I need, does anyone have any advice?