If you’re using @Melissa’s awesome Extended Date Table, you’re 95% of the way home.
Just bring your Excel list of holiday dates into Power BI. Let’s assume that table is called Holidays, and the column of holiday dates is “Dates”.
When you’re entering the query parameters, click the “Choose Column” button, select your Holidays[Dates] column , and it will automatically create a true/false column in your date table indicating whether the date is a holiday or not.
I hope this helpful.
- Brian
P.S. If you’ve already created the date table, you can just update the holiday column parameter manually by replacing “null” with the table and column reference (e.g., Holidays[Dates])