Can't display date properly

I’m trying to use get_posts to display one single news article in the homepage, I’d like for the date to show above the heading, and I’ve been trying to use <?php post_date(); to show the date inside of a <time> tag, for example:
<time class="updated" datetime="2011-09-16T14:43:13+00:00" pubdate="">9/16/11 2:00 P.M.</time>

Problem is, I keep getting errors with post_date.. Any suggestions? Thanks!