pcdr.marty

Automatically send HTTP Header “last-modified”. 
You can use post last modification time or creation date… (settings in administration)

Last modified header

Automatically send HTTP Header "last-modified".

Technology Wisdom

TW Post Modifier Tracker is a lightweight plugin that helps editorial teams, site managers, and content creators track content updates. 
It adds a new column to the WordPress Posts, Pages, WooCommerce Products, and Custom Post Types admin lists, showing the date/time of the last modification and the user who made the change, with no configuration needed.
Whether you’re managing a multi author site or auditing content activity, this plugin gives you clear visibility into post updates at a glance.
Features:
<ul>
<li>Adds a “Last Modified” column to the admin list table for posts, pages, products, and custom post types</li>
<li>Shows the exact date and time a post was last updated</li>
<li>Displays the user who last modified the content</li>
<li>Seamlessly integrates with the WordPress admin interface</li>
<li>No configuration required, Just install and activate</li>
<li>Includes a built-in tutorial page under Settings → Tutorial (TW PMT) with video guidance</li>
</ul>
<h3>License</h3>
This plugin is licensed under the GPL-2.0+ License. 
You can freely use, modify, and distribute it under the terms of this license. See the full license at: https://opensource.org/licenses/GPL-2.0

TW Post Modifier Tracker

Adds a Last Modified column in WordPress admin showing the date, time, and user of the last update for posts, pages, products and custom types.

Last modified header vs TW Post Modifier Tracker