Other community members have asked questions similar to this, but I couldn't find an answer for my situation - so I'm sorry if this is somewhat redundant.
For some background, I'm building a Nintex Workflow 2013 on a SharePoint 2013 site. I don't own Nintex for Office 365 or any developer software.
My workflow uses a lot of user interaction-based actions, mostly to-do tasks and reviews. I need a way to calculate due dates based on business days for each task and review action. Each task and review action has a different due date (i.e. 2 business days for the 1st review, 5 business days for the 2nd task), which is where the difficulty lies.
I've downloaded and tried to use the following user defined action (UDA) that was created for this problem: http://www.dox42.com/Modules/Workflow-Utils Unfortunately, the workflow runs through the action just fine, but when I look at my active tasks and reviews, the due date column is blank! Let me know if you've worked with this particular UDA before and know how to fix it. 
If you know how to create an inline function or user defined action, or if you have any other idea how to tackle this problem, I'd LOVE to hear it. I've spent way more time than I'd like to admit trying to fix this problem, and I'm pretty much at wit's end.
(I've already voted on this measure (https://nintex.uservoice.com/forums/229405-1-nintex-workflow-for-sharepoint/suggestions/6301144-inline-function-or-action-to-calculate-business-da), so hopefully that gets implemented soon.)
