[ninetyniner]

The local time is not included in HTTP request, therefore there is no way you can get it using PHP directly. You can solve this problem by asking your visitors to provide their GMT timezone once and then write it to the cookies. Another option is to use JavaScript for getting user's local time and then pass it to the PHP script. Something like this:

<script type="text/javascript">
var CurrentDate = new Date();
var CurrentHour = CurrentDate.getHours();
var CurrentMinute = CurrentDate.getMinutes();
window.location = "page.php?hour=" + CurrentHour + "&minute=" + CurrentMinute;
</script>

and then, in your PHP script:

// ...................................
$CurrentHour = $HTTP_GET_VARS["hour"];
$CurrentMinute = $HTTP_GET_VARS["minute"];
// ...................................