JavaScript 时差计算。转换为天数/小时/分钟/秒、计算某个时间到当前时间的差

var oldDate = '2017/02/07 00:00:00';
setInterval(function () {
                var activeDate = new Date();
                var diffDate = activeDate.getTime() - new Date(oldDate).getTime();

                // -----------------------

                var days = Math.floor(diffDate/(24*3600*1000));
                var leave1 = diffDate%(24*3600*1000);
                var hours = Math.floor(leave1/(3600*1000));
                var leave2 = leave1%(3600*1000);
                var minutes = Math.floor(leave2/(60*1000));
                var leave3 = leave2%(60*1000);
                var seconds = Math.round(leave3/1000);
                console.log( "<i style='color:red;'> " + days + " </i>天<i style='color:red;'> " + hours + " </i>时<i style='color:red;'> " + minutes + " </i>分<i style='color:red;'> " + seconds + " </i>秒");
            }, 1000);

　　计算某个时间到当前时间的差