title: JavaScript Time Zone Offset does not match Windows Offset
body: <p>I am having an unique issue using JavaScript. When running the below code my system which is in timezone <code>UTC -5 Eastern Standard Time</code> I am getting the value as <code>-4 UTC</code>, it should have been <code>-5 UTC</code>. </p>
  
  <p>Currently daylight saving is enabled but JavaScript seems to be unaware about it. What's wrong here, is there any other way to retrieve the correct offset?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var d = new Date();
  var tz = d.toString().split("GMT")[1].split(" (")[0];
  alert(tz);</code></pre>
  </div>
  </div>
  </p>
  
  <p><strong>Time and timezone from my system:</strong></p>
  
  <p><img src="https://i.stack.imgur.com/JAMpW.jpg" alt="enter image description here"></p>