business_time
business_time is an ActiveSupport add-on that gives you business -time helper methods such as "4.business_days.from_now".
This release adds configurable week start and end (if you're a baker, or live in the middle East, for instance), as well as several other small pullup requests. Further, Chris Wise shared with us an article he wrote showing how to integrate business_time with the holidays gem, so business_time automatically skips over holidays when doing calculations.