gistfile1.php

<?php $years = array(); $months = array(); ?>

<?php if(has_posts()): while(posts()): ?>

	<?php $y = date('Y', article_time()); $m = date('F', article_time()); ?>

	<?php if( ! in_array($y, $years)): $years[] = $y; ?>
	<h1><?php echo $y; ?></h1>
	<?php endif; ?>

	<?php if( ! in_array($m, $months)): $months[] = $m; ?>
	<h2><?php echo $m; ?></h2>
	<?php endif; ?>

	<p><?php echo article_title(); ?></p>

<?php endwhile; endif; ?>