Query posts dynamic date range

So, I’m using the following to filter posts:

                    $paged = is_front_page() ? get_query_var( 'page' ) : get_query_var( 'paged' );
                    $args['paged'] = $paged;
                    $args['post_type'] = 'coupons';
                    if(isset($_GET['sort']) && $_GET['sort'] == 'populair') {
                        $args['orderby'] = 'comment_count';
                        $args['order'] = 'desc';

                    }
                    elseif(isset($_GET['sort']) && $_GET['sort'] == 'best-beoordeeld-oplopend') {
                        $args['paged'] = $paged;
                        $args['post_type'] = 'coupons';
                        $args['orderby'] = 'meta_value';
                        $args['meta_key'] =  'gemiddeld_beoordeeld_met';
                        $args['order'] = 'ASC';  


                    }

                    query_posts($args);

So, I know how to filter by monthnum, but unfortunately that’s not sufficient. I am trying to query posts from the latest 7 days. Any clue, anybody?