Help Displaying Time

I want to display the time in a particular timezone (US Central) regardless
where the computer is located. I have written the script below which
displays the time in the Eastern, Central, Mountain, Pacific and Alaska time
zones in the US. It works okay if the computer is located in the Central
timezone but not if it is located elsewhere. I know how to get the UTC time
and the timezoneOffset but I can't figure out how to get from there to
Central time. Can anyone offer any suggestions?

<SCRIPT LANGUAGE="JavaScript">

var running = false
var timerID= null
var dayName=new Array(7)
dayName[0]="Sun"
dayName[1]="Mon"
dayName[2]="Tue"
dayName[3]="Wed"
dayName[4]="Thu"
dayName[5]="Fri"
dayName[6]="Sat"

function countDown() {
var now=new Date()
Present=now.getTime()

running = true
var theDay=now.getDay()
var theDisplayDay = dayName[theDay]
var theHour=now.getHours()
var theDisplayHour=theHour
var theMin=now.getMinutes()
var theSec=now.getSeconds()
document.forms[0].displayday.value= theDisplayDay
document.forms[0].displayhour.value= theDisplayHour+1
document.forms[0].displaymin.value= theMin
document.forms[0].displaysec.value= theSec
document.forms[1].displayday.value= theDisplayDay
document.forms[1].displayhour.value= theDisplayHour
document.forms[1].displaymin.value= theMin
document.forms[1].displaysec.value= theSec
document.forms[2].displayday.value= theDisplayDay
document.forms[2].displayhour.value= theDisplayHour-1
document.forms[2].displaymin.value= theMin
document.forms[2].displaysec.value= theSec
document.forms[3].displayday.value= theDisplayDay
document.forms[3].displayhour.value= theDisplayHour-2
document.forms[3].displaymin.value= theMin
document.forms[3].displaysec.value= theSec
document.forms[4].displayday.value= theDisplayDay
document.forms[4].displayhour.value= theDisplayHour-3
document.forms[4].displaymin.value= theMin
document.forms[4].displaysec.value= theSec
if (running) {
timerID=setTimeout("countDown()",1000)
}
}
function stopTimer() {
clearTimeout(timerID)
running=false
}

</SCRIPT>