A roughly daily rhythm
Circadian rhythms are internal timing patterns that influence when people tend to feel alert or sleepy. Light, darkness, and repeated schedules all help anchor that timing.
Use daylight deliberately
A short period outdoors early in the day can make the day-night contrast feel clearer. In the evening, reducing bright light and keeping a predictable wind-down can support that same contrast.
Consistency beats perfection
Shift work, travel, caregiving, and life events make regularity hard. Aim for small anchors, such as a stable wake time, rather than treating one late night as failure.
