js getTimezoneOffset() in php - php

Question

new Date().getTimezoneOffset()*(-1);
This JS function returns the UTC Time Zone of the machine in minutes. Is there any PHP function does the same thing?
Thank you..

Answer 1

<?php // RAY_easy_client_time.php
error_reporting(E_ALL);
// USE JAVASCRIPT TO GET THE CLIENT TIME AND COMPUTE THE OFFSET FROM THE SERVER TIME
// LOCATION OF THE SERVER - COULD BE ANYWHERE
date_default_timezone_set('America/Denver');
// DIFFERENCE OF SERVER TIME FROM UTC
$server_offset_seconds = date('Z');
// WHEN THE FORM IS SUBMITTED
if (!empty($_POST))
{
// JAVASCRIPT TELLS US THE CLIENT TIME OFFSET FROM GMT / UTC
$client_offset_minutes = $_POST["date_O"];
$client_offset_seconds = $client_offset_minutes * 60;
// THE TIME WE WANT AT THE CLIENT LOCATION
$client_timestring = 'TODAY 7:00AM';
// MAKE THE COMPUTATIONS, INCORPORATING THE OFFSET FROM GMT
$client_timestamp = strtotime($client_timestring) + $client_offset_seconds;
$server_timestamp = $client_timestamp + $server_offset_seconds;
$server_timestring = date('l, F j, Y \a\t g:i a', $server_timestamp);
echo "<br/>ACCORDING TO THE VALUE FROM PHP date Z";
echo "<br/>SERVER IS LOCATED $server_offset_seconds SECONDS FROM UTC";
echo "<br/>";
echo "<br/>ACCORDING TO THE VALUE FROM JS dateObject.getTimezoneOffset()";
echo "<br/>CLIENT IS LOCATED $client_offset_minutes MINUTES FROM UTC";
echo "<br/>";
echo "<br/>WHEN IT IS '$client_timestring' AT THE CLIENT, IT IS '$server_timestring' IN " . date_default_timezone_get();
}
// END OF PHP - USE HTML AND JS TO CREATE THE FORM
echo PHP_EOL; ?>
<form method="post">
<input name="date_O" id="dateTime_O" type="hidden" />
<input type="submit" value="CHECK CLIENT DATETIME" />
</form>
<!-- NOTE THIS WILL GIVE YOU THE VALUES AT PAGE-LOAD TIME, NOT AT SUBMIT TIME -->
<!-- MAN PAGE REF: http://www.w3schools.com/jsref/jsref_obj_date.asp -->
<script type="text/javascript">
var dateObject = new Date();
document.getElementById("dateTime_O").value = dateObject.getTimezoneOffset();
</script>

Answer 2

PHP, being server side, can only read what the client sends. It cannot tell the user timezone without being explicitly told by the user (or a user agent like the browser).
There are a couple ways to guess. You can look up the IP and guess timezone based on IP location by calling a location service (time expensive and can return incorrect results, I wouldn't recommend it).
You can also have your javascript make an ajax call to tell the server what the value for Date().getTimezoneOffset() is. Personally I would take this route.