One morning in Chapter 15, the narrator wakes up to find that what objects have been disappeared?

An excerpt of the narrator's novel about the typist starts off Chapter 15, after which the narrator turns off her desk light and retires from writing for the night. When she wakes up the next morning, she finds that calendars have been disappeared. She and the old man then wonder if winter will be perpetually in evidence on the island, since there are no more calendars to carry time forward toward spring.