title: DateTimeZone error: Unknown or bad timezone
body: <p>I am trying to run this script:</p>
  
  <pre><code>&lt;?php
  $d = new DateTime('now', new DateTimeZone('Asia/Kolkata'));
  $time = $d-&gt;format('H:i');
  
  echo $time;
  ?&gt;
  </code></pre>
  
  <p>but I got this error:</p>
  
  <p><code>Fatal error: Uncaught exception 'Exception' with message 'DateTimeZone::__construct() [&lt;a href='function.DateTimeZone---construct'&gt;function.DateTimeZone---construct&lt;/a&gt;]: Unknown or bad timezone (Asia/Kolkata)</code></p>
  
  <p>Though it works well for <code>Asia/Dacca</code> for example. What could be the problem and how to fix it?</p>