The Modern Forgery Hypothesis

[Mauro]

My summary, your mileage may differ:

1) Aberil was used, in print, in sufficient publications in the 18th or 19th centuries to fulfill my Theorem #1.
2) Furthermore, several references are to an "... an important Swiss epic poem written in dialect.", which reinforces #1. I mean, it was not in somebody's daily diary, it was a repeatedly published, well known and important poem
3) But as AI pointed out, above, it could also date to the era of the Voynich
4) And it may point to a Swiss/Germanic origin for these appended month names, or at least this one, whether the Voynich is old and real, or new and fake.

Rich

But why did Voynich use the rare 'Aberil' form instead of a common one to craft his forgery? And what about Jollet, Octembre etc., which purpose did that had for the forgery? And why write these marginalia at all, why this maniacal level of detail (which also required quite a good imagination)? Yes, it's possible someone will go to these lengths to craft his forgery, but it's weird: it's improbable. To me, it's more easily explained by someone who noticed the symbols were the Zodiac signs, years after the MS was produced, and scribbled the names of the months in his own dialect and orthography. And this improbability stacks over many other improbabilities (previously mentioned, I'll not repeat them).