Problem with countdown and different timezones

Hi!
On my website I need to have a counter that count down to a specific date and time. All works as it should except that I can’t figure out how to make the counter shoe the correct time for people in different timezones. If anyone would be able to help me as soon as possible I would be very thankful…

Cheers!

This is the actionscript:

this.onEnterFrame = function() {

var today:Date = new Date();
var currentYear = today.getFullYear();
var currentTime = today.getTime();

var targetDate:Date = new Date(currentYear,7,25,18,0,0);
var targetTime = targetDate.getTime();

var timeLeft = targetTime - currentTime;

var sec = Math.floor(timeLeft/1000);
var min = Math.floor(sec/60);
var hrs = Math.floor(min/60);
var days = Math.floor(hrs/24);
sec = string(sec % 60);
if (sec.length < 2) {
sec = “0” + sec;
}
min = string(min % 60);
if (min.length < 2) {
min = “0” + min;
}
hrs = string(hrs % 24);
if (hrs.length < 2) {
hrs = “0” + hrs;
}
days = string(days);

var counter:String = days + “:” + hrs + “:” + min + “:” + sec;
time_txt.text = counter;
}