<script type="text/javascript">
function checkTime(i){
if (i<10){
i="0" + i
}
return i;
}
var date = new Date('Thu May 12 2017 08:00:00 GMT+0800 (中国标准时间)');
date_value=date.getFullYear() + '-' + (date.getMonth() + 1) + '-' + date.getDate() + ' ' + checkTime(date.getHours()) + ':' + checkTime(date.getMinutes()) + ':' + checkTime(date.getSeconds());
//最后显示yyyy-MM-dd hh:mm:ss
</script>
效果图