Hi, Walster.
The This Week shortcode just runs the This Week widget.
You might just be able to hide those days with this CSS code:
.tribe-this-week-events-widget .tribe-this-week-widget-day-0,
.tribe-this-week-events-widget .tribe-this-week-widget-day-6 {
display: none;
}
If that’s not sufficient for your needs, you could customize the This Week widget’s template / content output via our Themer’s Guide.
If you need some coding help, you may want to ask your developer or reference our documentation and list of known customizers.