Interactive visualisation of circadian rhythm sleep disorders showing internal clock misalignment

Your sleep clock works perfectly — it's just set to the wrong time

Circadian rhythm disorders aren't about a broken clock — they're about misalignment between your internal rhythm and the external world. The biological mechanism runs fine; the phase is shifted. Drag the slider to shift the internal clock relative to the 24-hour day.

Clock Phase Alignment
Typical (0h shift)
Shift represents hours earlier (−) or later (+) than typical alignment
Internal rhythm aligned with external day
Phase Shift (hours)
−6h (ASPS) 0h +6h (DSPS)
Peak Sleep Pressure
23:00
Misalignment
0h

Delayed Sleep Phase Syndrome is most common in adolescence when the circadian rhythm naturally shifts later. The internal clock generates sleep pressure around 2–4 AM instead of 10–11 PM. The person isn't choosing to stay up late — their melatonin surge happens later. When forced to wake at 7 AM for school, they're cutting into the biological sleep window, creating chronic sleep deprivation. The rhythm itself runs at 24 hours and is perfectly healthy; it's just phase-delayed relative to social schedules.

Know This
Circadian rhythm disorders involve intact rhythms with misaligned timing — the internal clock runs normally but peaks at the wrong time relative to external demands.