通过时间字符串获取距离当前时间过去了多长时间

//字符串转换为时间戳
function getDateTimeStamp(dateStr){
    return Date.parse(dateStr.replace(/-/gi,"/"));
},

//获取指定时间距离现在过去了多少时间
function getDateDiff(dateStr){
    var me = this;
    var publishTime = me.getDateTimeStamp(dateStr)/1000,
        d_seconds,
        d_minutes,
        d_hours,
        d_days,
        timeNow = parseInt(new Date().getTime()/1000),
        d,

        date = new Date(publishTime*1000),
        Y = date.getFullYear(),
        M = date.getMonth() + 1,
        D = date.getDate(),
        H = date.getHours(),
        m = date.getMinutes(),
        s = date.getSeconds();
    //小于10的在前面补0
    if (M < 10) {
        M = '0' + M;
    }
    if (D < 10) {
        D = '0' + D;
    }
    if (H < 10) {
        H = '0' + H;
    }
    if (m < 10) {
        m = '0' + m;
    }
    if (s < 10) {
        s = '0' + s;
    }

    d = timeNow - publishTime;
    d_days = parseInt(d/86400);
    d_hours = parseInt(d/3600);
    d_minutes = parseInt(d/60);
    d_seconds = parseInt(d);

    if(d_days > 0 && d_days < 3){
        return d_days + '天前';
    }else if(d_days <= 0 && d_hours > 0){
        return d_hours + '小时前';
    }else if(d_hours <= 0 && d_minutes > 0){
        return d_minutes + '分钟前';
    }else if (d_seconds < 60) {
        if (d_seconds <= 0) {
            return '刚刚发表';
        }else {
            return d_seconds + '秒前';
        }
    }else if (d_days >= 3 && d_days < 30){
        return M + '-' + D + ' ' + H + ':' + m;
    }else if (d_days >= 30) {
        return Y + '-' + M + '-' + D + ' ' + H + ':' + m;
    }
}

//demo
 getDateDiff('2019-05-08 12:00:00');