获取上一个月的开始日期和结束日期

 

 获取最后一天 的下一个月第一天 减去  一天的毫秒数 就可以得到。

js 中 getMonth()  比实际月份数要小1.

 

//获取上一月的第一天

 //alert("month:"+now.getFullYear()+","+ now.getMonth());

 

 //var curTime = new Date(2013,(4-1),1);

 var curYear = curTime .getFullYear();

 var curMonth = curTime .getMonth();

 alert("cur:"+curTime.getFullYear()+"-"+(curTime.getMonth()+1)+"-"+curTime.getDate()); 

  

 var curMonthFirstDay = new Date(curYear,curMonth,1);

 var beforeMonth = curMonth-1;

 if(beforeMonth==-1){

   curYear = curYear-1;

 beforeMonth = 11;

 }

 

 var beforeStartDate = new Date(curYear,beforeMonth,1);

 alert(beforeStartDate.getFullYear()+"-"+(beforeStartDate.getMonth()+1)+"-"+beforeStartDate.getDate()); 

 

 var beforeMonthLastDay = new Date(curMonthFirstDay.getTime() - (24*3600*1000));

 alert(beforeMonthLastDay.getFullYear()+"-"+(beforeMonthLastDay.getMonth()+1)+"-"+beforeMonthLastDay.getDate());