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std::chrono::year_month:: year, std::chrono::year_month:: month

From cppreference.net
C++
Date and time library
std::chrono::year_month
constexpr std:: chrono :: year year ( ) const noexcept ;
(1) (since C++20)
constexpr std:: chrono :: month month ( ) const noexcept ;
(2) (since C++20)

Retrieves the year and month values stored in this year_month object.

Return value

1) Returns the stored std::chrono::year value.
2) Returns the stored std::chrono::month value.

Example

Run this code 
#include <chrono>
#include <iostream>
int main()
{
    std::cout << std::boolalpha;
    constexpr auto ym{std::chrono::year(2021)/std::chrono::July};  
    std::cout << (ym.year() == std::chrono::year(2021)) << ' ';
    std::cout << (ym.month() == std::chrono::month(7)) << '\n';
}

Output: 

true true