Recently I needed to calculate working days per month for a report that includes past complete months (e.g. January 2019) as well as the current, incomplete month (e.g. July 2019, as I write). In the case of the current, incomplete month, I have to grab the 'data_through_this_date' with the fileName for my process.
 
I also need to remove holidays.
 
My employer has six holidays and a policy of Saturday holiday = take prior Friday off, Sunday holiday = take following Monday off
 
Our holidays are:
- New Year's Day - January 1
 - Memorial Day - Last Monday in May
 - Independence Day - July 4
 - Labor Day - 1st Monday in September
 - Thanksgiving Day - 4th Thursday in November
 - Christmas Day - December 25
 
So, I built my workflow to follow this logic.
 
All you need to update are:
1. Date field of your data (mine is [Sales Month] in the text input)
2. Business logic for what holidays your employer has, and how they treat weekend holidays