The Light Prescription

Let today’s sun set your clock.

Your town, your wake time, today’s sun. A personal schedule of light, meals and caffeine, computed for this very day, because the times genuinely change every day.

Your location is used on this device only, to compute sun times. It is never sent anywhere.

This tool computes today's sunrise, solar noon, UVB window and sunset for your town, then folds your wake time, meals and caffeine around them. It runs entirely in your browser and needs JavaScript switched on. Nothing about you is ever sent anywhere.In the meantime, the general shape holds for everyone: bright outdoor light within an hour of waking, the last caffeine by early afternoon, dinner finished three hours before bed, and screens warm and dim from sunset. The verdict library holds the evidence for each.