Nocturne is for the rest of us — nurses, paramedics, police, drivers, crew, plant operators, people on call, new parents, anyone whose week does not run 9 to 5.
Put your roster in once. Nocturne works out where your body clock actually is and turns it into a day you can follow.
Twenty-four hours as one circle: your shift, your sleep, your nap, the windows where light helps and the windows where it hurts, and a predicted alertness curve running through the middle.
When to sleep, sized backwards from when you have to be up. When to nap, including the pre-shift nap that flattens the 03:00 low. When to get light and when to put sunglasses on for the drive home. Your last coffee, computed from your own caffeine clearance.
Six rotation templates — 4 on / 4 off, 12-hour days and nights, Continental, Pitman, permanent nights — that fill three months in one tap. Or drag in your own shifts.
A rolling sleep-debt ledger. Circadian drift: how far your lived schedule has pulled away from the clock you were born with. And the week ahead as a single heatmap, so you see the block of nights arriving before it lands on you.
Every recommendation can tell you the mechanism behind it. The engine is the published two-process model of sleep regulation, the light phase-response curve and first-order caffeine kinetics — running on your phone, with no wearable, no location permission and no account required to start.
Nocturne is educational software. It does not diagnose sleep disorders and is not a substitute for occupational health or your doctor. Never use a predicted alertness figure to decide you are safe to drive.