Dinner is at noon; supper is at night.
You're a Catholic or live in a Catholic dominated region, so you do what you do with names of meals.
I go by what I was raised with in regard to what names I use for meals, no matter where I am living. In most of the south, the midday meal was "dinner" and the evening meal was "supper." It still is, as far as my family and I are concerned.