Dodo Wonders by E.F. Benson

Dodo was lying in bed, just aware that a strip of sunlight on the floor was getting broader. She was not precisely watching it, but, half-consciously she knew that it had once been a line of light and was now an oblong, the rest of her perceptions were concerned with the fact that it was extremely pleasant to have been commanded in a way that made argument impossible, to remain where she was, and not to get up or think of doing so until the doctor had visited her, for there was nothing so repugnant to her mind at the moment as the idea of doing anything. She believed that she had breakfasted in a drowsy manner, and believed (with perfect truth) that she had gone to sleep again afterwards, for now the sunlight made a broad patch on the floor. Collecting her reasoning faculties, and remembering that her room looked due south, she arrived at the brilliant conclusion that the morning must have progressed towards noon.

That seemed something of a discovery, and having arrived at that conclusion she went to sleep again.