Plugin Auto Prune Posts — WordPress.com

Auto deletes expires (prunes) posts or pages after a certain amount of time. On a per category basis (single category, or all at once). Handy if you want to have posts with a limited timeframe such as offers, coupons etc.. Posts will auto delete on a per category basis: single category OR all categories at once. All (custom)post types are supported. (CPT support) Will also trash post attachments. Sends notification to site admin (can be turned off). No cronjob needed 🙂