gistfile1.js

//not very pretty

var dateFuture = new Date(2012,5,2,0,00,00);

function GetCount(ddate,iid){

  var dateNow = new Date(),
      amount = ddate.getTime() - dateNow.getTime(),
      days,
      hours,
      mins,
      secs,
      out;

  if(amount < 0){
    document.getElementById(iid).innerHTML="Now!";
  }else{
    days=0;
    hours=0;
    mins=0;
    secs=0;
    out="";
    amount = Math.floor(amount/1000);
    days=Math.floor(amount/86400);
    amount=amount%86400;
    hours=Math.floor(amount/3600);
    amount=amount%3600;
    mins=Math.floor(amount/60);
    amount=amount%60;
    secs=Math.floor(amount);

    if(days !== 0){
      out += days +" "+((days===1)?"day":"days")+", ";
    }
    if(hours !== 0){
      out += hours +" "+((hours===1)?"hour":"hours")+", ";
    }
    out += mins +" "+((mins===1)?"min":"mins")+", ";
    out += secs +" "+((secs===1)?"sec":"secs")+", ";
    out = out.substr(0,out.length-2);
    document.getElementById(iid).innerHTML=out;
    setTimeout(function(){
      GetCount(ddate,iid);
    }, 1000);
  }
}

window.onload=function(){
  GetCount(dateFuture, 'countbox1');
};