Shift to warmer colours on your Mac
You can schedule Night Shift to make your display colours warmer at a particular time of day or at sunset. Warm screen colours are easier on your eyes when you use your Mac at night or in low-light conditions. Also, exposure to bright blue light in the evening can make it harder to fall asleep. You can turn Night Shift on or off at any time — for example, if you’re in a darkened room.
Tip: You can also turn Night Shift on and off using Control Centre. Click 
in the menu bar, click Display, then click Night Shift. You can also use Siri to turn Night Shift on or off.
On your Mac, choose Apple menu
in the sidebar. (You may need to scroll down.)Click Night Shift, then do one of the following:
Shift to warmer colours at a set time at night: Click the Schedule pop-up menu, choose Custom, then choose when you want Night Shift to begin and end.
Shift to warmer colours at sunset: Click the Schedule pop-up menu, then choose Sunset to Sunrise.
To automatically turn on Night Shift at sunset, your Mac uses your location to determine when it’s nighttime for you. To use this option, you must turn on Location Services.
Shift to warmer colours manually: Turn on the “Turn on until [time]” option. Night Shift remains on until the next day or until you turn it off.
