S Hetjens

This plug-in adds a meta box to the post and page writing pages in wp-admin to set up an expiration date for that item. It uses the WordPress cron feature to be executed once a day.
After the expiration date the post will be in the trash can of WordPress. The plug-in does not delete any post, but WordPress will depending on the trash can settings.

Hetjens Expiration Date

This plug-in adds a meta box to the post and page writing pages in wp-admin to set up an expiration date for that item.

Cyril Batillat

By default, WordPress can protect each post with one and only password. This plugin gives you the possibility to assign multiple passwords on each post, with an expiration date.

p5 : Plenty of Perishable Passwords for Protected Posts

Specify multiple passwords for pages / posts / custom post  types. An expiration date can be set for each password.

Hetjens Expiration Date vs p5 : Plenty of Perishable Passwords for Protected Posts