设计思路应该没有问题呀，为什么总显示输出错误？

#include <stdio.h>
int main()
{
    int year = 2008;
    int month = 8;
    int day = 8;
int numbers;
if(year%4==0 && year%100!=0 || year%400==0)
{
  switch(month)
        {
        case 1:
        case 2:
             numbers = (month-1)*31 + day;
             printf("该日期对应该年的%d天",numbers);
             break;
        case 3:
        case 4:
        case 5:
        case 6:
        case 7:
        case 8:
             numbers = (month/2)*31 + ((month-3)/2)*30 + 29 + day;
             printf("该日期对应该年的%d天",numbers);
             break;
            default:
                numbers = ((month+1)/2)*31 + ((month-4)/2)*30 + 29 + day;
                printf("该日期对应该年的%d天",numbers);
             break;
  }
}
else
{
  switch(month)
        {
        case 1:
        case 2:
             numbers = (month-1)*31 + day;
             printf("该日期对应该年的%d天",numbers);
             break;
        case 3:
        case 4:
        case 5:
        case 6:
        case 7:
        case 8:
             numbers = (month/2)*31 + ((month-3)/2)*30 + 28 + day;
             printf("该日期对应该年的%d天",numbers);
             break;
            default:
                numbers = ((month+1)/2)*31 + ((month-4)/2)*30 + 28 + day;
                printf("该日期对应该年的%d天",numbers);
             break;
     }
    }
return 0;
}