Wherefore art thou, aberil?

[nablator]

Probably this has been settled a long time ago, but still I'd like to understand why the third letter is read as "e" and not something else.

I found an example of "e" written like this (15th century) with a detached "s" shape. The curvature is not as extreme as the "h" shape of aberil but other months such as decembre have shapes between "h" and "s". The discussion starts here: You are not allowed to view links. Register or Login to view.

The "s" shape is common in some spiky variants of Cursiva and Bastarda, but it is usually connected to the "c" shape under it.