title: How to fake time in javascript?
body: <p>I would like to mock the Date constructor so that whenever I call new Date(), it always return specific time.</p>
  
  <p>I found Sinon.js provide useFakeTimers to mock time. But the following code doesn't work for me.</p>
  
  <pre><code>sinon.useFakeTimers(new Date(2011,9,1));
  
  //expect : 'Sat Oct 01 2011 00:00:00' ,
  
  //result : 'Thu Oct 27 2011 10:59:44‘
  var d = new Date();
  </code></pre>