Years ago, I removed all timestamps from my posts. This was because people are biased when it comes to reading a post that is old. Google indexes date information on your page too, which can cause people not to even click through to your site.
Though I couldn’t tell how much of an impact this made, there was something not right about not including a timestamp on my posts. Since readers may want that kind of information, it becomes a question about designing my pages better for the reader. So I recently reintroduced timestamps on my posts. This time though, I decided not to provide the date the post was published. Instead, I use the date the post was modified. It’s way more relevant to a reader to provide the last date your post was updated rather than the first day it was posted.
In WordPress, you can hack your theme to provide the date your post was modified by inserting this code:
Last modified:<?php the_modified_time(' F j, Y'); ?>
Personally, I like providing this information at the end of posts. That way, it’s indexed by Google, but it’s not right at the top of the page.