Doug Wollison

Unpublish is a very simple plugin that does one simple thing: it adds a button to the Edit Post screen.
This button will appear on published posts/pages/etc, which on click will save the post as pending rather than keeping it published.
<h3>Usage Documentation</h3>
Click the button if you no longer want the post published.

Unpublish

Adds a one click "Unpublish" button to the WordPress edit screen; switches the status to pending.

gtuk

The plugin adds a datetime box to your edit pages to set a unpublish date to posts, pages, and custom post types.
After you set a unpublish date the post will we updated at the given time and become a draft. 
The plugins works with posts, pages and custom post types

Gtuk unpublish posts

Adds the possibility to set an upublish date to pages, posts and custom post types.

Unpublish vs Gtuk unpublish posts