I think a good author makes it explicit.
Here’s a sci-fi web novel I read years ago, where a couple of the characters end up being immortal in different ways, and in one case they show exactly how far that can go (in the context of the story) even without invoking heat death.
On a large enough clock, the hour hand could have easily visible marks for not just minutes, but also seconds. If I were an architect or whatever I would try to make that the floor of a lobby or something.