Wordpress Ratings for Comments section

I had a freelancer put a comment rating tool on my Wordpress site (up and down votes). The comments are sorted by popularity with most popular at the top. However I need a ratings tool that counts and sorts comments by popularity of the last xxxx days. I would assign a number and I want to be able to change the number if I decided to. When you bid for this project please specify how you plan to do this. Also let me know if you have any questions.