js比較時間年月日時分秒

function compareTime(){
    var beginTime = "2019-5-16 17:20:0";
    var endTime = "2019-5-16 16:39:32";

    var beginTimes =beginTime.replace(/-/g,"/");
    var endTimes =endTime.replace(/-/g,"/");
    console.log("beginTimes         =" + beginTimes); 
    console.log("endTimes           =" +endTimes); 
    var a =(Date.parse(endTimes)-Date.parse(beginTimes))/3600/1000;
    if(a<0){
        console.log("endTime小!");
    }else if (a>0){
        console.log("endTime大!");
    }else if (a==0){
        console.log("相等!");
    }
}