<script>

  //计算当月总天数

  function getCountDays() {

          var curDate = new Date();

          /* 获取当前月份 */

          var curMonth = curDate.getMonth();

         /*  生成实际的月份: 由于curMonth会比实际月份小1, 故需加1 */

         curDate.setMonth(curMonth + );

         /* 将日期设置为0, 这里为什么要这样设置, 我不知道原因, 这是从网上学来的 */

         curDate.setDate();

         /* 返回当月的天数 */

         return curDate.getDate();

  }

  //计算该月总周数

  function getWeekCounts( year, month ) {

      var lastDay = new Date(year, month, ).getDate();  //这个月的最后一天  --->(拿到这个月有多少天 )

      return Math.ceil(lastDay / );

  }  

  //第一周天数

  function getFirstWeek() {

      var month0 = new Date().getMonth();   //当前月所处月份

      var yeah0 = new Date().getFullYear();    //当前所处年

      var firstDate1 = new Date(yeah0, month0,).toString('yyyy-MM-dd');    //该月的第一天的年月日。

      var first = new Date(firstDate1).getDay();       //该月第一天是周几   （日一二三四五六   ----对应数字：0、1、2、3、4、5、6）

      var endhao = ;     // 周六

      var week1_day = endhao - first + ;

      return week1_day;

  }

  //计算当月每周多少天

  function getWeekOfDay(){

    var month0 = new Date().getMonth()+;   //当前月所处月份

    var yeah0 = new Date().getFullYear();    //当前所处年

    var weeks = getWeekCounts( yeah0, month0 );   //当前月的总周数

    var days = getCountDays();   //当前月的总天数

    var week1,week2,week3,week4,week5;

    week1 = getFirstWeek();   //第一周天数     week2、week3、week4、week5第几周天数

    if(weeks==){

        week2 = week3 = ;

        week4 = days - week1 - week2 -week3;

        document.write('第一周：'+week1+' ,第二周：'+week2+' ,第三周：'+week3+' ,第四周：'+week4);

    }else{

        week2 = week3 = week4 = ;

        week5 = days - week1 - week2 -week3 - week4;

        //alert(week5);

        document.write('第一周：'+week1+' ,第二周：'+week2+' ,第三周：'+week3+' ,第四周：'+week4+' ,第五周：'+week5);

    }

  }

  getWeekOfDay();

  </script>