#include <iostream>
using namespace std;

int year = 1945;
int month = 5;
int day = 9;
tm tm {0, 0, 0, day, month-1, year-1900};
time_t victoryDate = mktime(&tm);

char sDate[20];
strftime(sDate, 20, "%Y-%m-%d",
    localtime(&victoryDate));

cout << "sDate: " << sDate;