title: Wordpress - list posts by modified date
body: <p>How do I list my posts in Wordpress ordered by modified date instead of created date?</p>
  
  <p>I have it as  </p>
  
  <pre><code>&lt;?php $posts=query_posts($query_string . '&amp;orderby=post_modified&amp;order=ASC'); ?&gt;  
  &lt;?php if (have_posts()) : while (have_posts()) : the_post(); ?&gt;  
  </code></pre>
  
  <p>Having orderby=title does sort the posts by title but my above query doesn't work.<br>
  Looks like orderby=post_modified isn't recognized.</p>