Night Shift is a built in software feature of

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and

macOS macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

. It was introduced in 2016–2017 into

in iOS 9.3 and into

in macOS Sierra 10.12.4. The feature changes the

color temperature Color temperature is a parameter describing the color of a visible light source by comparing it to the color of light emitted by an idealized opaque, non-reflective body. The temperature of the ideal emitter that matches the color most clos ...

of the display towards the warmer part of the

color spectrum The visible spectrum is the band of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' (or simply light). The optical spectrum is sometimes consider ...

that reduces some of the blue light from the screen.

Apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

claims that the feature may help users have a better night's sleep by filtering blue wavelengths from the display, which suppress melatonin biosynthesis. The feature is similar to the functionality f.lux provides.

Effectiveness

Changing the color temperature of the display from blue towards yellow (without dimming the screen) was shown to have no effect on sleep outcomes (sleep latency, duration, efficiency and wake after sleep onset) in a 2021 study on 167 college undergraduates and to be insufficient for preventing the impact on melatonin suppression. In mice, yellow colors disrupted the mouse body clock more than equally bright blue colors.

Compatibility

The Night Shift feature is compatible with all

64-bit In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit central processing units (CPU) and arithmetic logic units (ALU) are those that are based on processor registers, a ...

iOS devices running on iOS 9.3 and above and Macs from 2012 and later running on macOS Sierra 10.12.4 and above.

Functionality

The feature can be turned on in Settings (in iOS) and in System Preferences (in macOS) and can be toggled on or off manually in the

Notification Center Notification Center is a feature in iOS, iPadOS, macOS and watchOS that provides an overview of alerts from applications. It displays notifications until the user completes an associated action, rather than requiring instant resolution. User ...

(in macOS) or in the Control Center (in iOS). The feature can be enabled or disabled with

Siri Siri ( , backronym: Speech Interpretation and Recognition Interface) is a digital assistant purchased, developed, and popularized by Apple Inc., which is included in the iOS, iPadOS, watchOS, macOS, Apple TV, audioOS, and visionOS operating sys ...

in iOS and macOS. The feature can set so it is enabled at sunset and turn off at sunrise (the default) or turned on and off on a custom schedule. The feature when set to enable at sunset and disable at sunrise relies on the user's approximate location to determine the time of sunset and sunrise. The user can also customize the intensity of Night Shift in Settings (iOS) or System Preferences (macOS).

References

{{macOS IOS MacOS

Effectiveness

Compatibility

Functionality

See also

References