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'));