In your opinion, did the writing of the VM start closer to 1412 or closer to 1440?

[Mark Knowles]

The only reason for people to vote outside of the broad range instead of inside of the narrow range is if they have something like a theory about authorship - which is fine. But it is remarkable that these tend to need later dates rather than earlier.

I suspect that this is coincidence more than anything else.

My dating of the Rosettes Folio to the 1430s is due to the Council of Basel being called by Pope Martin V in 1430.

Gérard Cheshire, for example, dates the manuscript to around 1444 as that was when a volcanic eruption occurred near the island of Ischia.

For those who think Hartlieb wrote the Voynich the dating is later due to the period he was active.

These three later datings are quite independent and so it is coincidental that they happen to be later.