Nocturne · last updated 31 July 2026
Nocturne is provided by Szymon Dziedzic. You may use it on any device you own, for personal or professional purposes, under Apple's standard Licensed Application End User License Agreement, which these terms sit alongside: apple.com/legal/internet-services/itunes/dev/stdeula.
Pro is available as a monthly or a yearly subscription.
Nocturne without Pro is a complete app: today's plan, the roster, the sleep log, the caffeine ledger, the nap planner and the next three days of the forecast are free and stay free.
Nocturne implements published chronobiology — the two-process model of sleep regulation, the light phase-response curve and first-order caffeine kinetics. It computes where your circadian clock is likely to be from the schedule you entered.
That is a model, not a measurement. Nocturne does not read a wearable, does not sample your temperature or melatonin, and cannot know how you actually slept unless you tell it. Individual variation is large. Treat every time it gives you as a well-reasoned starting point to adjust from, not as a reading taken off your body.
Nocturne is educational software. It does not diagnose, treat or prevent any condition, including shift work sleep disorder, insomnia, sleep apnoea and circadian rhythm disorders. It is not a substitute for your doctor or your employer's occupational health service. If you are persistently exhausted, falling asleep unintentionally, or worried about your sleep, speak to a clinician.
Do not use Nocturne while driving or operating machinery. Never use a predicted alertness figure to decide that you are safe to drive: the app cannot see how tired you actually are, and a plan that says you should be alert is not evidence that you are. Your employer's rules on hours, rest and fitness for duty come before anything this app suggests.
What Nocturne stores, and where, is set out in the Privacy Policy. You own what you enter. You can delete it, and your account with it, from inside the app.
Nocturne is provided as it is. We do not promise it will be free of defects or available without interruption, and to the extent the law allows we are not liable for loss arising from its use. Nothing here limits rights you have as a consumer that cannot be limited.