I agree. The "correct" answer is extremely unnatural. Its not like the calendar walked around to another place. It might make sense it they had used keys or sweater, something you actually move and often leave in random places (do you see my keys? Do you see my coat?). But kalendrar is a really strange item to use as an example, calendars often dont change places, it's why our brain "fixes" it to "have you seen" which is how you ask about things that are lost or out of their place. "Have you seen my car?" "Have you seen John?"
American English does not use calendar to mean diary, at least not in my 67 years of experience. Or perhaps it's that we use "diary" differenty. A diary is where you write your private thoughts, like a journal. Maybe you mean what we would call a "day-timer" or pocket calendar....two countries divided by a common tongue!