work days

I'm a newbie, so I'll apologize ahead of time if the answer is obvious.

We have a Power BI that pulls SQL data with items name, expected revenue & date of delivery.  

Created a visual, that uses the date of delivery and summarization of expected Revenue by Month

We would like to show Expected Revenue by month (based upon how many working days are in a month), to give us revenue per day like the following

I assume that I should create a manually entered table that has the days per month and somehow associate it with the SQL Queries "Date of Delivery" Month value, once I have that relationship, I can then create a new column which divides revenue by days of the month number derived by the association????