Ah, I understand the thing about moons. Months pretty much used to be calculated by lunar cycles, so literally 'first moon' is talking about the first full lunar moon cycle in a year. That is why it is technically correct, but still an anachronism. This is also present in other languages; For instance, the english word 'month' actually has the same etymological root as 'moon'.
There might be different languages in the world, but the underlying logic of characters representing a concept is how written language works in the first place. Only reasons I see that all the languages cannot be unified is due to connotations attached to concepts due to regional zeitgeists, as well as unique ephemeral ideas (like the word zeitgeist).
Or to put it in present-day terms, memes of the past have ruined communication between people.