WordPress doesn’t have a built-in capability to automatically delete posts. However, you can enable such functionality with the help of Post Expirator plug-in.
(1) Install Post Expirator plugin from within the WordPress admin dashboard.
Note: Refer to my previous article on rating if you want to know about the steps required to install a WordPress plugin.
(2) There is no options page for this plugin. In order to work with Post Expirator, you need to add a new post. You will be able to find a new section titled – Post Expirator on the right side of the dashboard
You can also select an existing post and update with the relevant expiry option.
(3) Select Enable Post Expiration checkbox and provide the relevant year, month and day
(4) It is also possible to specify the manner in which the post should expire. For instance, you can ask the plugin to place the relevant post into the draft section besides deleting it by selecting Delete option.
Post Expirator plugin will be useful if you run contests on your blog so that the related post will be automatically deleted as soon as the contest is over thus preventing users from participating in it.