There could be situations when you have to delete your posts or pages after/on a particular date. For example you are running a contest in your website and on timely manner you are adding polls, clues and rules for the contest.
The Post Expirator plugin allows the user to set expiration dates for both posts and pages. There is a configuration option page in the plugins area that will allow you to seperataly control whether or not posts/pages are either deleted or changed to draft status. Additionally you can also choose to have the post categories change at expiration time. If you choose to change the post category, the default action of changing the status will be ignored.
The plugin hooks into the wp cron processes and runs every minute by default, but can be configured to use any cron schedule (hourly, twicedaily, daily, etc).
The expiration date can be displayed within the actual post by using the [postexpirator] tag.
Here is an example screenshot in use.