Who wants to manually update the copyright date on their active blog? Nobody. Even though it’s best practice to keep your copyright date current with the last revision of a website, this can be difficult with an active blog.

Worse is the fact that it only has to be done once annually. If your blog is active and you’re paying attention, there’s at least a few days delay while you recover from the New Year before you bother updating the copyright date.

Everything else on the website is generated dynamically, so why not the copyright date? Sure, we could just have it display the current year, and that’s fine as long as you update the site at least once every year, but it’s not guaranteed. Besides, there’s an even cooler way, at least if you’re using WordPress. It involves the descriptively named get_lastpostmodified() function and PHP >=5.3’s DateTime class:

<small>©<?php $datetime = new DateTime(get_lastpostmodified());
         echo $datetime->format('Y'); ?> [Name]</small>

First, we grab the timestamp of the most recent update to any post. Then we feed that into a new DateTime object. Finally, we print out just the year.

Unfortunately, get_lastpostmodified() does not support UTC, only GMT, otherwise I’d use that. Annoyingly, the WordPress devs seem to consider these two time zones interchangeable. For our purposes, GMT and UTC are close enough, and the resultant code is quite similar:

<small>©<?php $datetime = new DateTime(get_lastpostmodified('gmt'), new DateTimeZone('gmt'));
         echo $datetime->format('Y'); ?> [Name]</small>

And there you go, a dynamically updating copyright notice suitable for your blog footer, that will keep the date current with the date of the last update to your blog.