Among the conditions for the validity of one’s fasting is that the person does not become insane, not even for a moment during the fasting day. If a person loses his sanity during the day or during part of the day, even for a moment, then his fasting would be invalidated. As well, it is conditional for the validity of one’s fasting that he does not lose consciousness during the entire fasting day, that is, from the dawn until sunset. If he lost consciousness for part of the day only, this does not invalidate the fast. On the other hand, sleeping does not invalidate the fast, even if one slept all day long.