I wonder how many libraries correctly handles the date 1712-02-30 in the Swedish calendar (according to Wikipedia the only official 30th of February in history)?
https://en.wikipedia.org/wiki/List_of_non-standard_dates#Feb...
Tried using ncal like in the examples in that blog post, but it did not work correctly using either Julian or Gregorian. Of course the Swedish calendar from 1700-1712 was neither, but somewhere in-between, because of the (failed) attempt to gradually move from one to the other.
> https://en.wikipedia.org/wiki/List_of_non-standard_dates#Feb...
Meta: one can also link to this article, which redirects:
* https://en.wikipedia.org/wiki/February_30
But that redirect (intentionally or not) doesn't include the fragment part of the URL, so it might not have satisfied the other poster's intent.