With much ado, I decided on this snippet to extract the name of the month from the number of the month.
<h4>{{ "1000-" ~ month ~ "-10" | date(format="%B") }}</h4>
I give it a fake year and day, and only extract a month, as I am iterating on an array of posts grouped by month. This is fine, but there has to be a better way to do this. Thoughts?