특정 날짜의 주 수를 결정하는 방법은 무엇입니까?

#include <iostream>
#include <ctime>

using namespace std;

int main() {
  // Get the current date
  time_t now = time(0);
  tm *ltm = localtime(&now);

  // Get the day of the week for January 1st
  tm jan1 = *ltm;
  jan1.tm_mon = 0;
  jan1.tm_mday = 1;
  int dow_jan1 = jan1.tm_wday;

  // Calculate the number of days between January 1st and the current date
  int days_since_jan1 = now - mktime(&jan1);
  int weeks_since_jan1 = (days_since_jan1) / 7;

  // Check if the current date is within January 1st to January 6th
  int week_number;
  if (weeks_since_jan1 == 0) {
    week_number = 1;
  } else {
    week_number = weeks_since_jan1;
  }

  cout << "The week number for " << asctime(ltm) << " is: " << week_number << endl;

  return 0;
}