by Paul Kaiser on WordPress.org
Schedule content to automatically expire and change at a certain time, and notify people of expiration.

The Content Scheduler options screen, where you determine what happens when the expiration date is reached.
Content Scheduler lets you control when content automatically expires, what to do with that content when it expires, and optionally provide notification to site contributors when the content expired.
You control what happens upon expiration, including:
Content Scheduler can also notify you:
This reminder helps you keep content fresh, providing a reminder that content is out of date and needs updated or replaced. Content Scheduler lets you use notification tools without making any changes to content upon expiration, if you’d like.