Thread:Kingdomhearts12/@comment-22439-20141004003807/@comment-24199126-20141222145709

Yes, bad weather can make a coronation less than welcoming, so even if Elsa turned twenty-one a few months prior, the real world connection suggests she may have an official birthday that's recognized in the summer months to facilitate attendance at such a ceremony.

But of course, this is all guesswork on my part; if you want a concrete answer, you can always try tweeting at Jennifer Lee on Twitter and pray she responds :)