test.cpp

#include <iostream>
#include <chrono>
#include <iomanip>
#include "ctime"


auto convert_to_timepoint(int years, int months, int days) {
  //perform checks, do division, modulus and stuff...
  years -= 1900; //epoch
  std::tm date = {};
  date.tm_year = years;
  date.tm_mon = months;
  date.tm_mday = days;

  return std::chrono::system_clock::from_time_t(std::mktime(&date));
}


template<typename Clock, typename Duration>
std::ostream &operator<<(std::ostream &os, const std::chrono::time_point<Clock, Duration> &timep) {
  auto converted_timep = Clock::to_time_t(timep);
  os << std::put_time(std::localtime(&converted_timep), "%Y %b %d %H:%M:%S");
  return os;
}

int total_time = 11000;

//1991 Jan 1
//auto start_date= convert_to_timepoint(1991, 0, 100);

bool is_first_day_of_month(std::chrono::time_point &point);

int main() {
//  std::cout << start_date;

  for (int current_time = 0; current_time < total_time; ++current_time) {
    auto calendar_date= convert_to_timepoint(1991, 0, current_time);

    if (is_first_day_of_month(calendar_date)) {
      std::cout << current_time << std::endl;
    }
  }


  return 0;
}

bool is_first_day_of_month(std::chrono::time_point &point) {
  return false;
}