title: How to make a DateTime string that changes depending on time zone?
body: <p>I'm in the middle of writing a website, and I got this marvellous idea. I would have my contact page change depending on the time zone it was viewed from.</p>
  
  <p>Examples:</p>
  
  <p>When viewed in the local time-zone (GMT +1):</p>
  
  <pre><code>I can be reached between 08:30 and 17:30
  </code></pre>
  
  <p>When viewed in New York (GMT -5):</p>
  
  <pre><code>I can be reached between 03:30 and 12:30
  </code></pre>
  
  <p>In San Francisco (GMT -8):</p>
  
  <pre><code>I can be reached between 00:30 and 09:30
  </code></pre>
  
  <p>In Beijing (GMT +8):</p>
  
  <pre><code>I can be reached between 16:30 and 01:30
  </code></pre>
  
  <p>... You get the idea.</p>
  
  <p>I'm not sure where I should start. I know of moment.js but I'm not sure if it's suitable for this purpose, 'specially considering the fact that I want this to be automatically determined by the user's current location.</p>
  
  <p>I'm using Node.js with Express.js for the server, and jQuery on the client-side. Any help?</p>