C语言实现代码如下：
int main(){
int daytab[12] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
char weekname[][7] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "sat" };
int i, m, d, week, days;
printf("Input date:month=?,day=?n");
scanf("%d%d", &m, &d);
if ((m <= 0 || m > 12) || (d <= 0 || d > 31))
printf("Date Error");
else{
days = d;
for (i = 0; i < m - 1; i++)
days = days + daytab[i];
week = (days + 5) % 7;
printf("It is %s dayn",weekname[week]);
}
return 0;
}
实现结果如下：
