title: How to mock the browser's timezone?
body: <p>I want to test a location feature in a web site, to make this test I need to try different time-zones. I obtain the timezone with a javascript code, calling the following function:</p>
  
  <pre><code>var offset = new Date().getTimezoneOffset();
  </code></pre>
  
  <p>Now this function returns to me 180 because I am in Argentina, I need to test with different time-zones. Somebody knows how to do this?
  Many thanks!!</p>