//获取当前时间，格式YYYY-MM-DD

    function getNowFormatDate() {

        var date = new Date();

        var seperator1 = "-";

        var year = date.getFullYear();

        var month = date.getMonth() + 1;

        var strDate = date.getDate();

        if (month >= 1 && month <= 9) {

            month = "0" + month;

        }

        if (strDate >= 0 && strDate <= 9) {

            strDate = "0" + strDate;

        }

        var currentdate = year + seperator1 + month + seperator1 + strDate;

        return currentdate;

    }

<script type="text/javascript">

function realSysTime(clock){

    var now = new Date();

    var year = now.getFullYear();

    var month = now.getMonth();

    var date = now.getDate();

    var day = now.getDay();

    var hour = now.getHours();

    var minu = now.getMinutes();

    var sec = now.getSeconds();

    month = month+1;

    var arr_week = new Array("星期日","星期一","星期二","星期三","星期四","星期五","星期六");

    var week = arr_week[day];

    var time = year+"年"+month+"月"+date+"日"+" "+week+" "+hour+":"+minu+":"+sec;

    clock.innerHTML=time;

}

window.onload=function(){

    window.setInterval("realSysTime(clock)", 1000);

}

</script>

<div id="clock"></div>