title: How do I test my browser timezone dependent application againts different timezones?
body: <p>I'm making a Javascript web application that depends on user's browser time zone.</p>
  
  <p>For example, whenever I check the UTC offset, I find it to be +5.5 only.</p>
  
  <p>How do I test if it works in other time zones as well? I specially want to see how it works with US time zones.</p>
  
  <p>I use Firefox mostly. Is there any configuration setting I can edit? I tried changing my system time zone, but it didn't work.</p>