it not only transforms the room, but makes objects needed for specific tasks, entities that would belong in the setting
Yes, that is exactly what 826 did. What you've added is just a time limit, which barely makes any difference unless you weave a specific narrative reasoning and backstory that could only work with time-limited calendar.
Anymore like it? Like what, transforms a room's interior? There are a couple, but I cannot recall it off my head. Or did you mean "just an everyday object but weird"? There are a lot of them, and they kinda can't stand by their description only. Those objects are kinda boring by itself, you need to explore on "why" and "how" of the object to grab people's attention.
You gotta ask question like, why is it a calendar? What if I write in another language? What if I dictate an American to write in Bahasa Indonesia, for example—in which the writer won't know what they're writing? Why it has power to summon setting-specific objects and entities? What if I wrote in past date? What if it runs out of pages? What if I draw something on it? What if I wrote paradoxes or purely abstract concepts? What if it's outside a room?
