Javascript into a usable variable in ASP.net

JavaScript
1

How do you pull out a value for “tz” into a usable variable in ASP.net?

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Timezone</title>
<script type="text/javascript">
    function timezone(){
           var offset = new Date().getTimezoneOffset();
           document.getElementById('tz').innerHTML=offset;
     }
</script>
</head>
<body>
  <div id="tz"></div>
  <input type="button" Value="TimezoneButton" onclick="timezone();" />
</body>
</html>
2

You don’t…

Ideally you would put that value into a hidden field, that field would need to be runat=“server” so on postback you can read the value (granted you can also read form submission data, but I highly recommend against doing that).