Changing at to @ for Comments date/time stamp

It seems like this would be simple but I can’t figure out how to simply change my comments date stamp from Aug. 20, 09 at 1:00PM to Aug.20, 09 @ 1:00PM.

I’m using the benevolence theme.
I adjusted my comments.php template to be able to use threaded comments and now have no idea how to change the time/date stamp.

Here is a chunk of my revised comments.php code.

<?php if ( have_comments() ) : ?> 

	<br />
<a href="#commentform" title="<?php _e("Leave a comment"); ?>">LEAVE A COMMENT</a>
<br /><br />

	<div class="navigation">
		<div class="alignleft"><?php previous_comments_link() ?></div>
		<div class="alignright"><?php next_comments_link() ?></div>
	</div>

	<ol class="commentlist">
    <?php wp_list_comments(array('type=comment','reply_text'=>'<span class="reply-box">Reply</span>')); ?>
	</ol>

	<div class="navigation">
		<div class="alignleft"><?php previous_comments_link() ?></div>
		<div class="alignright"><?php next_comments_link() ?></div>
	</div>
 <?php else : // this is displayed if there are no comments so far ?>

	<?php if ( comments_open() ) : ?>
		<!-- If comments are open, but there are no comments. -->

	 <?php else : // comments are closed ?>
		<!-- If comments are closed. -->
		<p class="nocomments">Comments are closed.</p>

	<?php endif; ?>
<?php endif; ?>

<?php if ( comments_open() ) : ?>

<?php paginate_comments_links( $args ) ?>
<!--for breaking comments into pages. -->

<div id="respond">

<?php comment_id_fields(); ?>

<h3><?php comment_form_title( 'Leave a Reply', 'Leave a Reply to %s' ); ?></h3>
<div class="cancel-comment-reply">
	<small><?php cancel_comment_reply_link('Cancel Reply'); ?></small>
</div>

<?php if ( get_option('comment_registration') && !is_user_logged_in() ) : ?>
<p>You must be <a href="<?php echo wp_login_url( get_permalink() ); ?>">logged in</a> to post a comment.</p>
<?php else : ?>

Thanks