hide expired coupons on a website page

Team,
Was this issue ever solved? Is there a way to remove the expired coupons from a particlar page on the website?

Please visit http://www.couponbum.com/new and you will notice that there are expired coupons that appear listed in between active coupons. I am using this shortcode on that page:

[LISTINGS orderby=’post_date’ order=’desc’ show=20]

I would still like the most recently published coupons to appear at the top, however, I would like to hide all expired coupons. Only active coupons should show on this page. Not sure how to accomplish this.

Thanks for the help.