Dogan Ucar

WP Last Modified adds the ‚last_modified_date‘ shortcode to your WordPress installation. This shortcode shows the last timestamp of your post/page. Simply use the „format“ attribute for custom date formats (it uses PHP’s date() function). 
The “description” attribute enables a brief description which changes has been made with the last modification. 
WP Last Modified shows also the actual revision of and the publication date of the post/page. 
You can customize the text which will be shown under each post/page under settings -> WP Last Modified Settings. You can also hide one of the elements if you do not want them.
With version 1.1.0, WP Open Last Modified was renamed to WP Last Modified.
Features:
<ul>
<li>last modification timestamp of a post/page</li>
<li>publication timestamp of a post/page</li>
<li>timestamp format customizable</li>
<li>revision count</li>
<li>custom text with placeholders</li>
<li>last modification description</li>
<li>excluding single posts/pages from displaying the last modification timestamp</li>
</ul>

WP Last Modified

This plugins adds the last modified date, current revision and the publication date of your post/page. Simply use the shortcode [last_modified_date]

Clifford Paulick

<h4>All Available Shortcode Arguments</h4>
<pre>
'timestamp' => '', // or use the 'post_id' and 'field_timestamp' arguments
'format' => 'c', // see https://www.php.net/manual/en/function.date.php
'time_zone' => '', // defaults to WP's General Settings time zone (if valid PHP time zone), else UTC. Only supports a PHP named time zone -- see https://www.php.net/manual/en/timezones.php
'field_name' => '', // the raw name (including the `wpcf-` prefix if a Types field) or a custom field that should have a UTC timestamp as its value
'post_id' => '', // applicable if using the 'field_timestamp' argument - defaults to current post if empty
</pre>
<h4>Shortcode Examples</h4>
1) 
Shortcode: <code>[tk_timestamp_human timestamp="1608299220"]</code>
(Assuming your WordPress General Settings time zone is set to ‘Europe/Amsterdam’) 
Expected Result: <code>2020-12-18T14:47:00+01:00</code>
2) 
Shortcode: <code>[tk_timestamp_human timestamp="1608299220" time_zone="America/Chicago"]</code>
Expected Result: <code>2020-12-18T07:47:00-06:00</code>
3) 
Shortcode: <code>[tk_timestamp_human timestamp="1608299220" time_zone="UTC"]</code>
Expected Result: <code>2020-12-18T13:47:00+00:00</code>
4) 
Shortcode: <code>[tk_timestamp_human timestamp="1608299220" time_zone="America/Chicago" format="j F, Y"]</code>
Expected Result: <code>18 December, 2020</code>
<h4>Global Function</h4>
The <code>tk_timestamp_to_human_wp_all_export()</code> global function is available as a wrapper for the shortcode, using all its defaults except requiring the Timestamp argument and optionally passing the Format and Time Zone parameters.
This can be handy for using with WP All Export (<a href="http://www.wpallimport.com/tour/export-developer-friendly/" rel="nofollow ugc">http://www.wpallimport.com/tour/export-developer-friendly/</a>), such as to export a custom field that’s a UTC timestamp value to a human-readable format, such as if the system you’re moving the data to requires a specific format.

TK Timestamp to Human Readable Date

Given a timestamp (assumed in UTC), convert to a human-readable date format using PHP named time zones.

WP Last Modified vs TK Timestamp to Human Readable Date