The summer solstice provides the greatest opportunity to be exposed to the health benefits of natural daylightExtended evening daylight at the summer solstice reduces the need to use indoor LED light before going to bed
June 20, the summer solstice, offers the greatest opportunity to take advantage of the healing properties of sunlight because it is the longest day of the year. It also has the fewest hours of darkness to illuminate with electric light before we retire to bed. Exposure to the harmful effects of evening blue-rich LED and fluorescent lights can be minimized.
the evidence for the healing power of natural daylight is substantial. Large-scale prospective studies show that people exposed to the most outdoor natural daylight are the healthiest and live the longest. Their rates of cardiovascular disease and diabetes are significantly less than those who spend most of their time indoors.