C# 中返回星期的函数

函数如下：

代入参数年y,月m,日d 即可返回所得的星期

public static string getWeekDay(int y, int m, int d)
     {
              if(m==1) {m=13;y--;}
                if(m==2) {m=14;y--;}   
              int week = (d + 2 * m + 3 * (m + 1) / 5 + y + y / 4 - y / 100 + y/400) % 7 + 1;
                string strweek="";
                switch (week)
         {
             case 1:
                 strweek = "星期一";
                 break;
             case 2:
                 strweek = "星期二";
                 break;
             case 3:
                 strweek = "星期三";
                 break;
             case 4:
                 strweek = "星期四";
                 break;
             case 5:
                 strweek = "星期五";
                 break;
             case 6:
                 strweek = "星期六";
                 break;
             case 7:
                 strweek = "星期日";
                 break;
         }
         return strweek;
     }