I php您可以根据所需的日期创建锚定类。我还没有测试过，但应该是这样的：

    // your relevant html parent element
    <div class="<?php echo getOlderPostsClassName( \'5/5/2012\',the_time() ); ?>">

    function getOlderPostsClassName($untilDate, $wordpressPostDate)
    {
       $start = strtotime($untilDate);
       $end = strtotime($wordpressPostDate);
       if ($start-$end > 0)
       {
          return \'My_css_class_for_older_posts\';
       }
       else
       {
       return \'\';
       }
    }

.My_css_class_for_older_posts h2{
    color:red;
 }