include leap year

int dayOfYear(int year, int month, int day){    int months[13] = {
   0,31,30,28,31,30,31,31,30,31,30,31}, i, days = 0;    if( (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) // is leap year        months[2] = 29;    for(i = 1; i < month; i++)        days += months[i];    days += day;    return days;}