C语言实现天数倒计时功能

#include<stdio.h>
void date1(int year,int month,int day,int days);
void date2(int year,int month,int day,int days);
int main(void)
{
 int Year,Month,Day,Days;
 printf("Enter three numbers:");
 scanf("%d %d %d %d",&Year,&Month,&Day,&Days);
 if((Year%4==0 && Year%100!=0) || (Year%400==0))
 date1(Year,Month,Day,Days);
 else
    date2(Year,Month,Day,Days);
 return 0;
}
void date1(int year,int month,int day,int days)
{
 int i,j;
 j=days;
 i=month;
 int MONTH[12]={31,29,31,30,31,30,31,31,30,31,30,31};

 if(days<=(MONTH[month-1]-day))
 printf("%d days after %d,%d,%d is %d,%d,%d",j,year,month,day,year,month,days+day);
 else
 {
     days=days-(MONTH[month-1]-day);
     while(days>MONTH[i])
     {
      days=days-MONTH[i];
      i++;