How to Detect User'S Timezone

How to automatically detect user's timezone?

Use javascript solution

http://www.onlineaspect.com/2007/06/08/auto-detect-a-time-zone-with-javascript/

Demo should show your timezone in select box.

http://onlineaspect.com/examples/timezone/index.html (Dead link)

How to detect user's timezone?

To summarize Matt Johnson's answer in terms of code:

<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js">
</script>
<script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/jstimezonedetect/1.0.4/jstz.min.js">
</script>
<script type="text/javascript">
  $(document).ready(function(){
    var tz = jstz.determine(); // Determines the time zone of the browser client
    var timezone = tz.name(); //For e.g.:"Asia/Kolkata" for the Indian Time.
    $.post("url-to-function-that-handles-time-zone", {tz: timezone}, function(data) {
       //Preocess the timezone in the controller function and get
       //the confirmation value here. On success, refresh the page.
     });
  });
</script>

Get timezone from users browser using moment(timezone).js

var timedifference = new Date().getTimezoneOffset();

This returns the difference from the clients timezone from UTC time.
You can then play around with it as you like.

get client time zone from browser

Look at this repository pageloom it is helpful

download jstz.min.js and add a function to your html page

<script language="javascript">
    function getTimezoneName() {
        timezone = jstz.determine()
        return timezone.name();
    }
</script>

and call this function from your display tag

How to detect the timezone of a client?

Unfortunately this information is not passed in HTTP headers.

Usually you need cooperating JavaScript to fetch it for you.

Web is full of examples, here is one http://www.coderanch.com/t/486127/JSP/java/Query-timezone

Getting the client's time zone (and offset) in JavaScript

Using getTimezoneOffset()

You can get the time zone offset in minutes like this:

var offset = new Date().getTimezoneOffset();
console.log(offset);
// if offset equals -60 then the time zone offset is UTC+01

var millis = new Date(dateStr).getTime();

Date date = new Date(millis);