计算时间差，返回相差的天、时、分、秒

 function getInterval(start, end) {
            //两个日期相差的毫秒数
            var interval = end - start;
            //定义相差的天数、小时数、分钟数、秒数
            var day, hour, minute, second;
            interval /= 1000;
            day = Math.round(interval / 60 / 60 / 24);
            hour = Math.round(interval / 60 / 60 % 24);
            minute = Math.round(interval / 60 % 60);
            second = Math.round(interval % 60);
            return {
                day: day,
                hour: hour,
                minute: minute,
                second: second
            }
        }
        var d1 = new Date();
        var d2 = new Date(2022, 9, 8);
        console.log(getInterval(d1, d2))