It's how Apple sells the feature: https://support.apple.com/en-us/HT207513 https://support.apple.com/en-us/HT207513 >Studies have shown that exposure to bright

It's how Apple sells the feature: https://support.apple.com/en-us/HT207513 https://support.apple.com/en-us/HT207513 >Studies have shown that exposure to bright blue light in the evening can affect your circadian rhythms and make it harder to fall asleep. Night Shift uses your computer's clock and geolocation to determine when it's sunset in your location. It then automatically shifts the colors in your display to the warmer end of the spectrum.