std::chrono::month_weekday
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <chrono> | ||
| class month_weekday; | (since C++20) | |
The class month_weekday represents the n-th weekday of a specific month, of some yet to be specified year.
month_weekday is a TriviallyCopyable StandardLayoutType.
Member functions
| constructs a month_weekday(public member function) | |
| retrieves the stored month and weekday_indexed values (public member function) | |
| checks whether the contained month and weekday_indexed are valid (public member function) | 
Nonmember functions
| compares two month_weekdayobjects(function) | |
| outputs a month_weekdayinto a stream(function template) |