var date1=new Date();  //开始时间

 var date2=new Date();    //结束时间

 var date3=date2.getTime()-date1.getTime()  //时间差的毫秒数

 ------------------------------

 //计算出相差天数

 var days=Math.floor(date3/(24*3600*1000))

 //计算出小时数

 var leave1=date3%(24*3600*1000)    //计算天数后剩余的毫秒数

 var hours=Math.floor(leave1/(3600*1000))

 //计算相差分钟数

 var leave2=leave1%(3600*1000)        //计算小时数后剩余的毫秒数

 var minutes=Math.floor(leave2/(60*1000))

 //计算相差秒数

 var leave3=leave2%(60*1000)      //计算分钟数后剩余的毫秒数

 var seconds=Math.round(leave3/1000)

 alert(" 相差 "+days+"天 "+hours+"小时 "+minutes+" 分钟"+seconds+" 秒")

 var minute = 1000 * 60;

 var hour = minute * 60;

 var day = hour * 24;

 var halfamonth = day * 15;

 var month = day * 30;

 function getDateDiff(dateTimeStamp){

 var now = new Date().getTime();

 var diffValue = now - dateTimeStamp;

 if(diffValue < 0){

  //非法操作

  //alert("结束日期不能小于开始日期！");

  }

 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="发表于" + parseInt(monthC) + "个月前";

  }

  else if(weekC>=1){

  result="发表于" + parseInt(weekC) + "个星期前";

  }

  else if(dayC>=1){

  result="发表于"+ parseInt(dayC) +"天前";

  }

  else if(hourC>=1){

  result="发表于"+ parseInt(hourC) +"个小时前";

  }

  else if(minC>=1){

  result="发表于"+ parseInt(minC) +"分钟前";

  }else

  result="刚刚发表";

 ? return result;

 }