如何将PHP会话变量中的JavaScript变量值保留在同一页面上

I'm using JavaScript to get the user timezone name. I want that timezone name into PHP session variable in the same page. JavaScript is client side and PHP is server side. How will it be possible? Are there any ways to this?

You could make an ajax post and post the value you want to a php file and there update the php session variable like

$_SESSION['timezone'] = $_POST['timezone']