java\javascript 通用算出一个月有多少天

   private static int getDaysOFMonth(String timeMonth) throws Exception {
        if (timeMonth == null) {
            throw new Exception("时间对象为空值");
        }
        //格式不正确 正确格式YYYYMM
        if (timeMonth.length() < 6) {
            throw new Exception("时间格式不正确");
        }
        Date Currentdate = new Date(Integer.parseInt(timeMonth.substring(0, 4)), Integer.parseInt(timeMonth.substring(4, 6)), 1);
        Date Lastdate = new Date(Integer.parseInt(timeMonth.substring(0, 4)), Integer.parseInt(timeMonth.substring(4, 6)) - 1, 1);
        long diffDays = Currentdate.getTime() - Lastdate.getTime();
        return (int) (diffDays / (24 * 60 * 60 * 1000));
    }
//  int days=getDaysOFMonth("200812");

         /**
         * 当月天数 (YYYYMM)
         */
        function daysOfMonth(Month) {
            var currentMonth=new Date(Month.substring(0,4),Month.substring(4,6),1);
            var lastMonth=new Date(Month.substring(0,4),Month.substring(4,6)-1,1);
            var diffDays=currentMonth-lastMonth;
            return (diffDays/( 24 * 60 * 60 * 1000));
        }
//alert(daysOfMonth('200812'));