Non-24-Hour Sleep-Wake Disorder is a serious disorder of the body’s circadian system, in which a person’s clock runs (generally) much longer than 24 hours and they are unable to entrain to a 24-hour daily cycle. Instead, their sleep time progresses later and later each day, going all the way around the clock. It is also called Free Running Disorder. Without proper treatment the person is unable to meet regular daily commitments and so, without suitable accommodations, unable to hold a normal job, so this is a real disability. And in some people the current treatment are ineffective.