#include <iostream>
#include <chrono>

using namespace std;

void log(int result) {
    cout << "then his age is " << result << endl;
    if (result > 50) {
        cout << "you are old";
    } else if (result > 18) {
        cout << "you are an adult";
    } else {
        cout << "you are still a child";
    }
}

int main() {
    auto date = chrono::system_clock::now();
    auto year = format("{:%Y}", date);
    int birth_year;
    int current_year = stoi(year);
    cout << "enter your year of birth: ";
    cin >> birth_year;

    int age = current_year - birth_year;

    log(age);
    return 0; 
};

this is my code, i am using vscode gcc version 14.1.0
this error appeared:
‘format’ was not declared in this scope

i am new, i dont understand what does the error mean and i cannot find solution online

i changed the c++ standard on C/C++ Configurations to gnu++20 and the error message still appears.