帮忙看一下哪里错了
#include <stdio.h>
int main()
{
/* 定义需要计算的日期 */
int year = 2008;
int month = 8;
int day = 8;
int sum=0;
switch(month)
{
case 1;sum+=0;break;
case 2;sum+=31;break;
case 3;if(year%400==0)
{sum+=29;}
else{sum+=28;}break;
case 4;sum+=31;break;
case 5;sum+=30;break;
case 6;sum+=31;break;
case 7;sum+=30;break;
case 8;sum+=31;break;
case 9;sum+=31;break;
case 10;sum+=30;break;
case 11;sum+=31;break;
case 12;sum+=30;break;
printf("%d.%d.%d是今年的第%d天",year,month,day,sum);
return 0;
}