Jan Štětina

Hides posts older than given date or amount of time relative to present (see <code>(http://php.net/manual/en/function.strtotime.php strtotime)</code>).
You can also choose a capability – users who have this capability will then see all posts. And if you enter <code>none</code>, even admins will be excluded.
Uses <code>posts_where</code> and <code>getarchives_where</code> filters.
Developed for private use, but has perspective for more extensive usage. I can’t guarantee any support in the future nor further development, but it is to be expected. Kindly inform me about bugs, if you find any, or propose new features: zaantar@zaantar.eu.

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Hides posts older than given amount of time.

Mario Peshev

DevriX

DX Out of Date allows you to display a notification box on your posts 
when a given amount of time has passed. Quite handy when writing tutorials 
or any content that might get outdated due to external factors – now you 
could automatically notify your readers after a given period.
You can configure the expiration time of your posts in the admin panel. Valid time units are days, months and years.
Currently the plugin options are:
<ul>
<li>Period – “amount” of “duration” units (1 to 40)</li>
<li>Duration frame (days, months, years)</li>
<li>Message – the message format for the notification box</li>
<li>Enable by default – a checkbox for enabling the message on all posts by default</li>
<li>Enable post status in Dashboard – a checkbox for adding an extra column in the Dashboard for the outdated status of posts</li>
<li>Post types to affect – allows you to choose which post types for display the message for</li>
<li>Position of the message – choose whether the message should be displayed at the top or at the bottom of a post’s content</li>
<li>Background color – Choose a background color for the message</li>
<li>Text color – Choose a text color for the message</li>
<li>Custom CSS – Add custom CSS rules to the message box</li>
</ul>

DX Out of Date

Display a notification box on the single view of your outdated posts, given a set amount of time (configurable).

Hide Old Posts vs DX Out of Date