I don't know why it couldn't be done with some custom code executed in the frm_view_order hook. That's the only hook in Formidable where you can modify any view query before the data is displayed. I don't know this for certain without testing the code, but I suspect that Formidable must be doing a query that looks for all data within a month. We would need to calculate the day of the week the last day of the month falls on, then figure out wht Friday's date is if is after the EOM and adjust the query's end date accordingly. It might take a developer a day to code, test, and document a project like this. There may be other ways to do this, but this is the way I would tackle it.