这里哪里有问题呢

#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,i;
    if(year%4==0)
        i=1;
        else
        i=0;

    switch(month)
    {
        case 1:sum=0;
        break;
        case 2:sum=0+31;
        break;
        case 3:sum=0+31+28;
        break;
        case 4:sum=0+31+28+31;
        break;
        case 5:sum=0+31+28+31+30;
        break;
        case 6:sum=0+31+28+31+30+31;
        break;
        case 7:sum=0+31+28+31+30+31+30;
        break;
    }
    sum+=day;
    if(month>=2&&i==1)
    sum++;
    printf("%d年%d月%d日是今年的第%d天",year,month,day,sum);
    return 0;
}