01 / Follow the light — daylight and daily rhythm
Your day starts with a signal. Light reaching the eyes is one of the body’s strongest time cues. It helps distinguish biological day from biological night. The interesting part is contrast: a brighter, active day and a progressively dimmer, quieter evening—not a rigid sunrise routine.
Try it in your day
Try stepping outdoors within the first one to two hours after waking for five to ten minutes, then find another brief outdoor moment later. See whether earlier light changes how alert the morning feels or how naturally the evening winds down. Cloud, shade, a balcony or a doorway still counts. In the evening, lower bright overhead light and screen brightness when practical. This is ordinary daylight, not sun-gazing; use appropriate sun protection during prolonged exposure.