js毫秒数和日期相互转换

转载自：https://blog.csdn.net/tanqiaoxing/article/details/79865989  

【1】、毫秒数转换为具体日期

function getMyDate(str) {
    var oDate = new Date(str),
    oYear = oDate.getFullYear(),
    oMonth = oDate.getMonth()+1,
    oDay = oDate.getDate(),
    oHour = oDate.getHours(),
    oMin = oDate.getMinutes(),
    oSen = oDate.getSeconds(),
    oTime = oYear +'-'+ addZero(oMonth) +'-'+ addZero(oDay) +' '+ addZero(oHour) +':'+
addZero(oMin) +':'+addZero(oSen);
    return oTime;
}

//补零操作
function addZero(num){
    if(parseInt(num) < 10){
        num = '0'+num;
    }
    return num;
}
接口返回的毫秒数如果为string，需要转化为int

var dateTime = getMyDate(parseInt(data));

 data:  1537444800000

 dateTime：2018-09-20 20:00:00

【2】、日期转换为毫秒数

var secondsTime = new Date(dateTime).getTime();

 dateTime：2018-09-20 20:00:00

secondsTime:  1537444800000