How to Determine User Timezone in Web Applications?

Determining User Timezone

Many web applications require the ability to determine the user's timezone. This can be achieved in various ways, including PHP and JavaScript.

PHP Method

To obtain the user's timezone in PHP, you can utilize the $_SESSION superglobal. Create a session by calling session_start(). Then, define a session variable $_SESSION['time'].

To set this variable, you will need to send a request to a separate PHP file, timezone.php. In this file, extract the user's timezone from the $_GET['time'] parameter and assign it to $_SESSION['time'].

Here is a code snippet for timezone.php:

<code class="php"><?php
session_start();
$_SESSION['time'] = $_GET['time'];
?></code>

In the main PHP file where you wish to access the user's timezone, include the following code:

<code class="php">session_start();
$timezone = $_SESSION['time'];</code>

JavaScript Method

Using jQuery, you can determine the user's timezone as follows:

1. Include jQuery in the section of your HTML document.

2. Write the following JavaScript code:

   <code class="javascript">$(document).ready(function() {
       if ("<?php echo $timezone; ?>".length == 0) {
           var visitortime = new Date();
           var visitortimezone = "GMT " + -visitortime.getTimezoneOffset() / 60;
           $.ajax({
               type: "GET",
               url: "http://example.com/timezone.php",
               data: 'time=' + visitortimezone,
               success: function () {
                   location.reload();
               }
           });
       }
   });</code>

   Remember to replace http://example.com/timezone.php with the URL to your timezone.php file.

By executing this code, you can set the 'time' session variable and reload the page, making the user's timezone available as $timezone.

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