时间

let time=new Date().toLocaleString('chinese',{hour12:false});

  var now = new Date();
  var year = now.getFullYear(); //得到年份
  var month = now.getMonth(); //得到月份
  var date = now.getDate(); //得到日期
  var day = now.getDay(); //得到周几
  var hour = now.getHours(); //得到小时
  var minu = now.getMinutes(); //得到分钟
  var sec = now.getSeconds(); //得到秒
  month = month + 1;
  if (month < 10) month = "0" + month;
  if (date < 10) date = "0" + date;
  if (hour < 10) hour = "0" + hour;
  if (minu < 10) minu = "0" + minu;
  if (sec < 10) sec = "0" + sec;
  var time = "";
  time = year + "-" + month + "-" + date + " " + hour + ":" + minu + ":" + sec;

<script type="text/javascript">
    function addDay(datetime, days) {
        var old_time = new Date(datetime.replace(/-/g, "/")); //替换字符，js不认2013-01-                    31,只认2013/01/31
        var fd = new Date(old_time.valueOf() + days * 24 * 60 * 60 * 1000); //日期加上指                    定的天数
        var new_time = fd.getFullYear() + "-";
        var month = fd.getMonth() + 1;
        if (month >= 10) {
            new_time += month + "-";
        } else {
            //在小于10的月份上补0
            new_time += "0" + month + "-";
        }
        if (fd.getDate() >= 10) {
            new_time += fd.getDate();
        } else {
            //在小于10的日期上补0
            new_time += "0" + fd.getDate();
        }
        return new_time; //输出格式：2013-01-02
    }
    alert(addDay("2013-11-12", 1)); //弹出值：2013-11-13
</script>

var startDate1 ='2012-12-30 00:00:00' ;
let start1 = new Date(startDate1.replace(/\-/g, "\/"));
var startDate2 ='2012-12-30 13:13:02' ;
let start2 = new Date(startDate2.replace(/\-/g, "\/"));
start2 .getTime();// 获取时间戳 单位毫秒
console.log(start1,start1<start2) // Sun Dec 30 2012 00:00:00 GMT+0800 (中国标准时间) true

  var theTime = params.row.alarmDuration; // 秒
           var middle = 0; // 分
           var hour = 0; // 小时
           //parseInt() 函数可解析一个字符串，并返回一个整数
           if (theTime > 60) {
             middle = parseInt(theTime / 60);
             theTime = parseInt(theTime % 60);
             if (middle > 60) {
               hour = parseInt(middle / 60);
               middle = parseInt(middle % 60);
             }
           }
           var result = "" + parseInt(theTime) + "秒";
           if (middle > 0) {
             result = "" + parseInt(middle) + "分" + result;
           }
           if (hour > 0) {
             result = "" + parseInt(hour) + "小时" + result;
           }
    return h("span", result);