title: new Date(milliseconds) returns Invalid date
body: <p>I am trying to convert milliseconds to a date using the javascript using:</p>
  
  <pre><code>new Date(Milliseconds); 
  </code></pre>
  
  <p>constructor, but when I give it a milliseconds value of say 1372439683000 it returns invalid date. If I go to a <a href="http://www.ruddwire.com/handy-code/date-to-millisecond-calculators/">site that converts milliseconds to date</a> it returns the correct date.</p>
  
  <p>Any ideas why?</p>