js比較時間字符串相差幾分鍾

const compareTimeMin = (time1,time2) => {
    let m = 0;
    //判斷開始時間是否大於結束日期
    if(time1>time2)
    {
        m = 0;
    }else{
        //截取字符串，得到日期部分"2009-12-02",用split把字符串分隔成數組
        var begin1 = time1.substr(0,10).split("-");
        var end1 = time2.substr(0,10).split("-");
        
         var beginTime1 = time1.substr(11,8).split(":");
         var endTime1 = time2.substr(11,8).split(":");
        //將拆分的數組重新組合，並實例成化新的日期對象
        var date1 = new Date(begin1[0] + '-' + begin1[1] + '-' + begin1[2]+ ' '+ beginTime1[0]+':' +beginTime1[1]+':'+beginTime1[2]);
        var date2 = new Date(end1[0] + '-' + end1[1] + '-' + end1[2]+ ' '+ endTime1[0]+':' +endTime1[1]+':'+endTime1[2]);    
        
        //得到兩個日期之間的差值m，以分鍾為單位
        m=parseInt(Math.abs(date2-date1)/1000/60); 
    }
    return m;
}