目标时间2-目标时间1，的转换并且兼容所有

function timeFormat(newTimeStr, oldTimeStr){
    newTimeStr = newTimeStr.replace(/-/g, "/"); 
    oldTimeStr = oldTimeStr.replace(/-/g, "/");
    var newTime = new Date(newTimeStr).getTime();
    var oldTime = new Date(oldTimeStr).getTime();
    var diffTime = newTime - oldTime;
    if(diffTime < 0){
        return "请确保参数顺序";
    }
    var hh = Math.floor(diffTime / 60 / 60 / 1000);
    hh = hh < 10 ? "0" + hh : hh;
    diffTime -= hh * 60 * 60 * 1000;
    var mm = Math.floor(diffTime / 60 / 1000);
    mm = mm < 10 ? "0" + mm : mm;
    diffTime -= mm * 60 * 1000;
    var ss = Math.floor(diffTime / 1000);
    ss = ss < 10 ? "0" + ss : ss;
    return hh + ":" + mm + ":" + ss;
}
timeFormat("2018-05-11 15:09:09", "2018-05-11 12:10:10");