Plan a wind-down routine before bed.
A wind-down routine has to start early enough to contain both the screen cutoff and the activities themselves, so the window is the larger of the two rather than their sum. Working back from target bedtime gives a specific start time — the thing that makes a routine happen — and the slack figure shows whether the plan is tight or comfortable. If slack is negative the routine cannot fit inside the screen-free window.
Wind-down start time
Wind-down window = max(screen cutoff minutes, reading + hygiene minutes); start time = target bedtime - wind-down window
These figures are estimates based on population-average formulas and are intended for training and recreational planning only. They are not medical advice. Consult a qualified health professional before starting or changing an exercise programme, particularly if you have an existing medical condition.
Thirty to sixty minutes suits most people. The consistency of the sequence matters more than its length — the same cues in the same order become a sleep signal.
Bright, engaging screen use close to bed delays sleep onset through both light and arousal. A dim e-reader is far less disruptive than a phone.
The activities do not fit inside your screen-free window. Either start earlier or shorten the routine — otherwise the screen cutoff quietly gets abandoned.