Months names are all one off?

[Bernd]

The weirdest thing about the VM is that literally everything is weird. It's not just one aspect, it goes down to the smallest detail. Everything looks somewhat familiar, but ultimately nothing appears to makes sense. Neither the main text, nor the drawings, marginalia or month names.
I do understand why the hoax hypothesis is popular, though I do not agree with it (yet).

An alternative hypothesis would be that, rather than a hoax or the work of a genius, the VM could be the end product of an improbable chain of misunderstandings by different people leaving their marks over time and that neither the original author(s) nor the people adding the marginalia or month names fully knew what they were doing. Somewhat but not 100%. Enthusiasts but not experts. Anyway, I think there is now plenty of evidence we are dealing with a quite complex history of the manuscript. I do not think that there is a simple answer.