title: Trying to clone a stdClass
body: <p>I'm trying to clone a stdClass object that have an attribut which is a DateTime. But it fails. It looks like the clone is not working. Should I wrote my own __clone() method?
  What is wrong here?</p>
  
  <p>The code:  </p>
  
  <pre><code>$object = new stdClass;
  $object-&gt;date = new DateTime();
  var_dump($object-&gt;date);
  
  $cloned = clone($object);
  $object-&gt;date-&gt;modify('+1 day');
  var_dump($cloned-&gt;date);
  </code></pre>
  
  <p>The output:</p>
  
  <pre><code>object DateTime (
      -&gt;date = string (19) '2013-04-11 11:54:00'
      -&gt;timezone_type = int 3
      -&gt;timezone = string (13) 'Europe/Berlin'
  
  object DateTime (
      -&gt;date = string (19) '2013-04-12 11:54:00'
      -&gt;timezone_type = int 3
      -&gt;timezone = string (13) 'Europe/Berlin'
  </code></pre>