Date.prototype.format = function(format){
    var o = {
    "M+" : this.getMonth()+1, //month
    "d+" : this.getDate(),    //day
    "h+" : this.getHours(),   //hour
    "m+" : this.getMinutes(), //minute
    "s+" : this.getSeconds(), //second
    "q+" : Math.floor((this.getMonth()+3)/3),  //quarter
    "S" : this.getMilliseconds() //millisecond
    }
    if(/(y+)/.test(format)) format=format.replace(RegExp.$1,
    (this.getFullYear()+"").substr(4 - RegExp.$1.length));
    for(var k in o)if(new RegExp("("+ k +")").test(format))
    format = format.replace(RegExp.$1,
    RegExp.$1.length==1 ? o[k] :
    ("00"+ o[k]).substr((""+ o[k]).length));
    return format;
}

<script type="text/javascript">
setInterval(function(){
    var time = new Date().format("hh:mm:ss");
    var date = new Date().format("yyyy-MM-dd");
    document.getElementById("Time").innerHTML=time;
    document.getElementById("Date").innerHTML=date;
},1000);

</script>
<div id="Date"></div>
<div id="Time"></div>