Custom Defined Week/Date Range Help

[Andrew Leonard]

I'm using MySQL Workbench and a 3rd party business intelligence platform that is connected to our database to format (aka make pretty) the outputs of the queries.

This question is primarily regarding the query setup. I have a query that outputs a "Leaderboard" of sales for our reps over the past week (rolling 7 days).

Currently, the previous week is set up as a rolling total of the past 7 days (including today) by using this:

WHERE sale_date BETWEEN curdate() - INTERVAL 6 DAY AND curdate()

This works great for giving me the numbers on a rolling week. However, I want to be able to find the numbers for the current work week (eventually the previous week too, but I can derive that from y'alls answers). To further make matters more complex, our work week isn't a normal work week. I would need to define our work week as "Friday to Thursday". If at all possible I would like to define this directly into the query as I don't have backend access to our SQL server (but I can get it if it's going to be impossible to do without).

I've tried searching around and tried a few things but haven't had any luck. I know my way around MySQL enough for the basics plus a little extra, but this seems to be way above my head.

Any help or direction will be greatly appreciated on how I can accomplish this.