std::chrono::month_weekday::month, std::chrono::month_weekday::weekday_indexed
From cppreference.com
                    
                                        
                    < cpp | chrono | month weekday
                    
                                                            
                    | constexpr std::chrono::month month() const noexcept; | (1) | (since C++20) | 
| constexpr std::chrono::weekday_indexed weekday_indexed() const noexcept; | (2) | (since C++20) | 
Retrieves a copy of the month and weekday_indexed objects stored in *this.
Return value
1) a copy of the std::chrono::month object stored in 
*this2) a copy of the std::chrono::weekday_indexed object stored in 
*this