can i reheat fish the next day?

Definitely reheat in the oven to freshen it but be careful not to cook it too long or it will dry. Also recommend if you're in a pinch put it in the microwave with a glass of water, I'm not sure exactly the chemistry of it, but it keeps things like breaded foods and pizza crust crisp and not soggy.

It's ok to re-heat but do it uncovered so the bread crumbs don't get soggy