取某一天是该月的第几周

   

 //取得某dd天在某mm月份是第几周 (c#)

 protected int WeekOfMonth(int yyyy,int mm, int dd)
    {
        DateTime FirstDay = new DateTime(yyyy, mm, 1);
        DateTime OneDay = new DateTime(yyyy, mm, dd);
        int FirstWeek = (int)FirstDay.DayOfWeek;
        int Week = dd - 1 + FirstWeek;
        return (Week / 7) + 1;
    }