@davedelong
Yes there are misconceptions around date and time, and yes calendars are not stable. Nevertheless, we try to make applications for humans, who expect to see dates as they know them. We don't try to predict the next political announcement about calendars.
Could you give your answer to my question above:
What is the next date after 2024-12-02?
Is it a valid question? Is it out of the scope of Foundation? What code would you use to calculate it? Existing functionality in Date and Calendar or a custom library? If I don't want to import any package for this calculation, could you recommend a solution?
[In case your answer is to use Calendar's date(byAdding:to:wrappingComponents:): do I need to bother about time and timezone? If I can give an immediate mental answer to this question, why I cannot do the same with computer calculations? Is the mental answer wrong, because I did not go into the trouble to think about the exact time?]
Regarding "domain-specific": everyone knows how to find the next date. School children also know. Domain-specific means you need an expert to get the correct answer. There is nothing specific in wall calendar dates. It is standard knowledge and it should belong to a standard library.