Javascript实现时间转换为多少天前

//实现时间转换，这篇文章发布时间为 2016/1/20 19:59:30 文章发表时间戳为：1453291170000于：11月前
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,"/"));
}

参考：http://caibaojian.com/timestamp.html

另一个选择：

function formatMsgTime (timespan) {

  var dateTime = new Date(timespan);

  var year = dateTime.getFullYear();
  var month = dateTime.getMonth() + 1;
  var day = dateTime.getDate();
  var hour = dateTime.getHours();
  var minute = dateTime.getMinutes();
  var second = dateTime.getSeconds();
  var now = new Date();
  var now_new = Date.parse(now.toDateString());  //typescript转换写法

  var milliseconds = 0;
  var timeSpanStr;

  milliseconds = now_new - timespan;

  if (milliseconds <= 1000 * 60 * 1) {
    timeSpanStr = '刚刚';
  }
  else if (1000 * 60 * 1 < milliseconds && milliseconds <= 1000 * 60 * 60) {
    timeSpanStr = Math.round((milliseconds / (1000 * 60))) + '分钟前';
  }
  else if (1000 * 60 * 60 * 1 < milliseconds && milliseconds <= 1000 * 60 * 60 * 24) {
    timeSpanStr = Math.round(milliseconds / (1000 * 60 * 60)) + '小时前';
  }
  else if (1000 * 60 * 60 * 24 < milliseconds && milliseconds <= 1000 * 60 * 60 * 24 * 15) {
    timeSpanStr = Math.round(milliseconds / (1000 * 60 * 60 * 24)) + '天前';
  }
  else if (milliseconds > 1000 * 60 * 60 * 24 * 15 && year == now.getFullYear()) {
    timeSpanStr = month + '-' + day + ' ' + hour + ':' + minute;
  } else {
    timeSpanStr = year + '-' + month + '-' + day + ' ' + hour + ':' + minute;
  }
  return timeSpanStr;
};

参考：http://www.cnblogs.com/malvina/p/5888479.html