Directory / plugin
p5 : Plenty of Perishable Passwords for Protected Posts
v1.4 · by Cyril Batillat
Specify multiple passwords for pages / posts / custom post types. An expiration date can be set for each password.
About this plugin
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.