Which manuscript is that?
It looks to me like in all cases, they are using a Latin form. September is the nominative, which you get in the second clip "the month that is called September".
I can't tell for sure without seeing the other month names in this MS.
It looks to me like in all cases, they are using a Latin form. September is the nominative, which you get in the second clip "the month that is called September".
I can't tell for sure without seeing the other month names in this MS.

