Does a consistent morning routine with daylight help you fall asleep more easily in the evening?

Daylight is the most important time-setter for your biological clock. Through specialised light-sensitive cells in the retina, morning light sends a signal to a small control centre in the brain that regulates your 24-hour rhythm. This mechanism is solidly supported by multiple studies.

People who spend more time outdoors during the day tend to fall asleep earlier in the evening on average. This emerged from a questionnaire study of around 500 people, and it held true for all sleep types, from early birds to night owls. This is an association, not an experiment, but the direction is clear.

Consistent morning habits reinforce this effect. Getting up at the same time every day, exercising, or being outside acts as a regular nudge to the clock that keeps your biological rhythm sharp. During the COVID lockdowns, when people went outside less and lost their daily structure, the number of sleep problems increased noticeably. Sleep scientists identify the loss of daylight and fixed routines as two of the most important non-stress-related causes.

For the morning specifically, there is also research into alarm clocks that simulate the light of a sunrise. The first indications are positive for sleep quality and how you feel during the day, but there are still very few well-designed studies on the topic, so firm conclusions are not yet possible.

An international panel of sleep and rhythm researchers advises getting as much bright light as possible during the day, preferably outdoors, and limiting bright light in the evening. Note that several members of that panel have ties to the lighting industry, which is worth bearing in mind. The underlying biology is sound: more daylight during the day sharpens the clock and lowers the threshold for falling asleep more easily in the evening.