Timeago is a jQuery plugin that makes it easy to support automatically updating fuzzy timestamps (e.g. "4 minutes ago" or "about 1 day ago") from ISO 8601 formatted dates and times embedded in your HTML (à la microformats).
First, load jQuery and the plugin:
<script src="jquery.min.js" type="text/javascript"></script>
<script src="jquery.timeago.js" type="text/javascript"></script>
Now, let's attach it to your timestamps on DOM ready:
<pre>
jQuery(document).ready(function() {
jQuery("abbr.timeago").timeago();
});
</pre>
This will turn all abbr elements with a class of timeago and an ISO 8601 timestamp in the title:
<abbr class="timeago" title="2008-07-17T09:24:17Z">July 17, 2008</abbr>
into something like this:
<abbr class="timeago" title="July 17, 2008">about 1 day ago</abbr>
As time passes, the timestamps will automatically update.
For more usage and examples: http://timeago.yarp.com/
For different language configurations: http://gist.github.com/6251
Copyright (c) 2008-2010, Ryan McGeary (ryanonjavascript -[at]- mcgeary [dot] org)