Months names are all one off?

[ReneZ]

I have a vague recollection that the Voynich MS isn't quite unique in this, and similar exceptions exist but are rare. It could well be useful to find such examples. My 'vague memory' is known to be wrong from time to time.

Ah, just found one again that has been discussed before. You are not allowed to view links. Register or Login to view.  is a very recent post showing the Byrhtferth diagram that has the same association between months and zodiac signs as the Voynich MS.

So while it is rare, it is not impossible or wrong.