Suppose I want to refer to a 24-hour period (from midnight till midnight). The word "day" can in fact mean "24 hours" (as in here), however it's somewhat ambiguous. I believe that if I say something like "just wait a day", most people will understand it in a common meaning. I could also say "just wait 24 hours", but that sounds a little weird to me, about as much as saying "I want 127.5 grams of cheese, please" in a store.
So how would a native speaker refer to the 24-hour period to avoid ambiguity (and being concise in the same time)? Maybe there is a fancy scientific word for it?