Do not show expired coupons

Hi,

On my homepage I have a list of recent coupons. Once a coupon is expired, I would not like to see it on my site anymore.
Now you still see the coupon and it is expired.
In Page setup I selected recent listings for the homepage. You can then enter a query string. I think I need to enter something here, but what? Now this is the only query I have: orderby=IDorder=desc.
Can someone help me with this?