> As confusing as that was, he always called lunch dinner into the modern age.

This is still a thing in parts of the UK (and possibly other places):

"The divide between different meanings of "dinner" is not cut-and-dried based on either geography or socioeconomic class. The term for the midday meal is most commonly used by working-class people, especially in the English Midlands, North of England and the central belt of Scotland."

https://en.wikipedia.org/wiki/Dinner#Modern