时间戳转时间格式

   //分钟
                   let timeM= parseInt(msg/1000/60%60); 
                   if(timeM<10){
                      timeM="0"+timeM;
                       }
                   //秒钟
                   let timeS=parseInt(msg/1000%60);
                   if(timeS<10){
                       timeS="0"+timeS;
                        }
                  let time=timeM+":"+timeS;