How to calculate number workday in Power Query and Power BI

I have a list of tasks in my database with different start dates and required finish dates organized in two columns. For each column, I want to create a new column to capture the "MAX", "MIN", "Average" date by Task ID for scheduled dates after the current year. Keep in mind that the dataset has millions of records that date back to 10 years but I want to create a Gantt Chart to capture the "WORKDAY" duration for the current year only. Image may be NSFW.
Clik here to view.