Why the month names aren't Voynichese?

[ReneZ]

But now I wonder how handwriting and book bindings can be dated with such precision.

At work, one of my colleagues had a sign on his door which explained the difference between dillettantes and specialists. 
The dillettante knows epsilon about everything and the specialist knows everything about epsilon.

One of the two aspects of Dunning-Kruger is that the dillettante is likely to massively underestimate how much there is to know about any (epsilon) topic. 
And each specific sub-topic has its own specialists, so only few people will know about it. At the same time, they are likely to know who are the specialists that know more about each sub-topic.

Just to say that this works for me. I can happily accept that knowledge exists (because it has been gathered and improved over generations of specialists) in which I have no insight whatsoever. It is not generally accessible, and the bit that is ('Google'), is not much more than 'epsilon'.