Отсчет времени до определенной даты

function timer() {
    var nowDate = new Date();
    var achiveDate = new Date(2013,0,28,17,0,0); //Задаем дату, к которой будет осуществляться обратный отсчет
    var result = (achiveDate - nowDate)+1000;
    if (result < 0) {
        var elmnt = document.getElementById('timer');
        elmnt.innerHTML = ' - : - - : - - : - - ';
        return undefined;
    }
    var seconds = Math.floor((result/1000)%60);
    var minutes = Math.floor((result/1000/60)%60);
    var hours = Math.floor((result/1000/60/60)%24);
    var days = Math.floor(result/1000/60/60/24);
    if (seconds < 10) seconds = '0' + seconds;
    if (minutes < 10) minutes = '0' + minutes;
    if (hours < 10) hours = '0' + hours;
    var elmnt = document.getElementById('timer');
    elmnt.innerHTML = days + ':' + hours + ':' + minutes + ':' + seconds;
    setTimeout(timer, 1000);
}
window.onload = function() {
    timer();
}

<script language='javascript' type='text/javascript'>
function fulltime ()   {
var time=new Date();
var newYear=new Date("jan,01,2011,00:00:00");   
var totalRemains=(newYear.getTime()-time.getTime());
 
if (totalRemains>1){
 
var RemainsSec = (parseInt(totalRemains/1000));
var RemainsFullDays=(parseInt(RemainsSec/(24*60*60)));
var secInLastDay=RemainsSec-RemainsFullDays*24*3600;
var RemainsFullHours=(parseInt(secInLastDay/3600));
if (RemainsFullHours<10){RemainsFullHours="0"+RemainsFullHours};
var secInLastHour=secInLastDay-RemainsFullHours*3600;
var RemainsMinutes=(parseInt(secInLastHour/60));
if (RemainsMinutes<10){RemainsMinutes="0"+RemainsMinutes};
var lastSec=secInLastHour-RemainsMinutes*60;
if (lastSec<10){lastSec="0"+lastSec};
 
document.getElementById("RemainsFullDays").innerHTML=RemainsFullDays+"<span id='Rem'> дн</span>";
document.getElementById("RemainsFullHours").innerHTML=RemainsFullHours+"<span id='Rem'> час</span>";
document.getElementById("RemainsMinutes").innerHTML=RemainsMinutes+"<span id='Rem'> мин</span>";
document.getElementById("lastSec").innerHTML=lastSec+"<span id='Rem'> сек</span>";   
setTimeout('fulltime()',10)    
}
 
else{
document.getElementById("clock").innerHTML="C НОВЫМ ГОДОМ !!!";
}
}
</script>
<style type='text/css'>
#clou_xs {position:relative;width:200px;height:150px;padding:10px;}
#clock {height:150px;text-align:center;font-size:13px;}
#RemainsFullDays {position:absolute;top:50%;left:40%;font-size:25px;}
#RemainsFullHours {position:absolute;bottom:1px;left:40px;font-size:15px;}
#RemainsMinutes {position:absolute;bottom:1px;left:87px;font-size:15px;}
#lastSec {position:absolute;bottom:1px;left:135px;font-size:15px;}
#Rem {font-size:11px;font-weight:normal;}
</style>
<div id='clou_xs'>
<div id='clock'>
до нового года осталось:
 
<span id='RemainsFullDays'></span>
    <span id='RemainsFullHours'></span>
    <span id='RemainsMinutes'></span>
    <span id='lastSec'></span>
</div>
</div>
<script language='javascript'>fulltime();</script>

timer(2022,2,12,0,12,33);
 
function timer($year, $month, $day, $hours, $minutes, $seconds) {
    var nowDate = new Date();
    var achiveDate = new Date($year, $month, $day, $hours, $minutes, $seconds); 
//остальной код остался прежним

setTimeout(timer, 1000);

var achiveDate = new Date(undefined, undefined, undefined, undefined, undefined, undefined);

setTimeout(timer, 1000);

setTimeout(function () {
    timer($year, $month, $day, $hours, $minutes, $seconds)
}, 1000);