js时间对比-转化为几天前,几小时前，几分钟前

function getDateDiff(dateTimeStamp){
    var minute = 1000 * 60;
    var hour = minute * 60;
    var day = hour * 24;
    var halfamonth = day * 15;
    var month = day * 30;
    var now = new Date().getTime();
    var diffValue = now - dateTimeStamp;
    if(diffValue < 0){return;}
    var monthC = diffValue/month;
    var weekC = diffValue/(7*day);
    var dayC = diffValue/day;
    var hourC = diffValue/hour;
    var minC = diffValue/minute;
    if(monthC >= 1){
        result = parseInt(monthC) + "月前";
    }else if(weekC >= 1){
        result = parseInt(weekC) + "周前";
    }else if(dayC >= 1){
        result = parseInt(dayC) +"天前";
    }else if(hourC >= 1){
        result = parseInt(hourC) +"小时前";
    }else if(minC >= 1){
        result = parseInt(minC) +"分钟前";
    }else{
        result = "刚刚";
    }
    return result;
}

转换标准时间为时间戳：

function getDateTimeStamp(dateStr){
    return Date.parse(dateStr.replace(/-/gi,"/"));
}

调用：

var timeStr = '2018-05-16 15:02:20',
      timeStamp = getDateTimeStamp(timeStr);
console.log(getDateDiff(timeStamp));