title: format - undefined is not a function for Date object
body: <p>I have following code: </p>
  
  <pre><code> var actualDate=new Date();
   actualDate.format("YYYY-mm-dd HH-MM-ss.l");
  </code></pre>
  
  <p>My browser complains about second row:</p>
  
  <pre><code>Uncaught TypeError: undefined is not a function
  </code></pre>
  
  <p>How to fix this issue?</p>