Wind down routine planner

Sleep onset is a letting-go, and letting-go is the one thing you cannot do on command at 11:47 pm because you suddenly remembered an email. A wind down routine works because it moves the decisions upstream: the caffeine cutoff is decided at 3 pm, the screens at 10, the argument with your inbox never happens because the phone is already in another room. Behavioural sleep medicine calls this stimulus control, and it is the best-evidenced non-drug intervention for sleep-onset problems — more durable than sleep hygiene lists because it is a schedule, not a set of aspirations.

Every offset in the planner is a half-life or a physiological lag. Caffeine sits 8 hours back because its half-life is 5–6 hours — half your 4 pm coffee is still aboard at 10 pm, cutting slow-wave sleep even when you fall asleep fine. Alcohol sits 3 hours back because it fragments the second half of the night as it clears. The warm shower sits 90 minutes back because the core-temperature drop it triggers takes that long to arrive. Nothing on the card is arbitrary; the rationale prints with each step. And if you don't have a bedtime to work backwards from yet, the bedtime calculator derives one from your wake time and sleep-cycle length.

Then the routine should fit 15 minutes, not shame you about the other 105. Set the time budget and the planner scales the in-home steps proportionally, and when two steps would land on the same minute it keeps the higher-impact one: screens off beats everything (arousal is the direct antagonist of sleep onset), then getting bed-ready, then a slow de-arousal activity, with the environmental niceties — the bath, the thermostat, the dimming — first to drop. What never compresses is the far end: caffeine, alcohol and meal cutoffs are half-lives and digestion windows, not preferences, so they stay on the card at their physiological times even in the shortest routine.

In three places, not just the caffeine cutoff. The cutoff does move first — a wolf's 4 pm cutoff only makes sense against a midnight bedtime — but the light and arousal steps move too. Wolves get the earliest dimming of any type (evening light pushes an already late-drifting clock later) and a 90-minute screen gap to outlast the second wind. Dolphins — the light, easily-disrupted sleepers — get a longer de-arousal buffer: screens off 90 minutes out and a 45-minute slow activity instead of 30. Lions mostly need protecting from one-more-task syndrome, and the rationale says so. Set your chronotype in the planner and the card rebuilds around it; the physiological anchors (caffeine, alcohol, digestion) never move, because a half-life is not a preference.