private int getMonthWeekDay(int y, int m, int weekNum) { DateTime d = DateTime.Parse(y + "-" + m + "-01"); int day = 1; if (weekNum == 1) { return(day); } else { int dw = DateTimeExd.GetWeekNum(d);//1号是星期几 if (dw == 0) { dw = 7; } if (weekNum == 2) { day = 1 + (7 - dw) + 1; //day = 1 + 7 - (7 - dw);//第一周 1号+下周隔7天-(本月1号没有的几个星期) } else { //day = 1 + 7 - (7 - dw); day = 1 + (7 * (weekNum - 1) - dw) + 1; } } return(day); }