Supper - a random midwest connection

Part of HOT TO GO! just triggered a core memory for me. Growing up we would visit my grandparents in rural southeast Missouri (very close to Elephant Rocks, which I bet several of you know) and we always found it kind of weird that our Granny would always say "dinner" instead of "lunch" and then "dinner" was "supper".

All of a sudden the "hurry up, it's time for supper" line hit me like a ton of bricks in reminding me of that. I'm curious how far consistent use of "supper" extends beyond southern Missouri if anyone is willing to chime in!