Night Shift Not Working on Mac? Here's the Fix

Sunset hit an hour ago and your screen is still its usual blue-white. Or it’s bright noon and your display is the orange of a sunset. Or Night Shift just won’t toggle on at all — the slider in System Settings → Displays → Night Shift does nothing.

Here’s how to fix it.

Confirm Night Shift is supported on your hardware

Night Shift requires:

• macOS 10.12.4 or later (every supported Mac qualifies on this front).
• A supported Mac model — basically every Mac from 2012 onwards.
• For Sunset-to-Sunrise scheduling: Location Services on, with a known location.

If you’re on a Mac mini headless or a Mac Pro driving older monitors, Night Shift still works — it’s a software color shift, not hardware-dependent.

Check the schedule

System Settings → Displays → Night Shift shows three controls:

• Schedule: Off, Sunset to Sunrise, or Custom.
• Manual: a “Turn On Until Tomorrow” toggle that overrides the schedule.
• Color Temperature: how warm the shift goes.

If “Manual” is on but the display doesn’t look warm, Night Shift is engaging but at too subtle a temperature — drag the warmth slider further toward “More Warm” to see if it’s just very mild.

If Schedule is set to “Sunset to Sunrise” but Night Shift never engages, Location Services is the likely cause.

Enable Location Services

Sunset/Sunrise needs to know where you are. System Settings → Privacy & Security → Location Services:

• Confirm Location Services is on at the top.
• Scroll down to “System Services,” click “Details.”
• Confirm “Time & Date” and “System Customization” are enabled.

If Location Services is off entirely, schedule-based Night Shift won’t work — switch to “Custom” with a manual time range, or enable Location Services.

If Location Services is on but Night Shift still doesn’t activate at sunset, your Mac may have a stale or wrong location. Open Maps (Applications → Maps) and check that it shows your actual location. If Maps shows the wrong city, Night Shift is using that wrong city’s sunset time. Toggling Location Services off and on, or restarting, refreshes it.

Reset corrupted display prefsSweep can wipe and rebuild stale display preference files when those are the cause. Get Sweep free →

Check it’s not a display profile issue

Some custom ICC profiles override Night Shift behavior. If you have a third-party ICC profile active (DisplayCAL, X-Rite, etc.), Night Shift may not engage or may engage subtly because the profile’s color management is at a different layer than Night Shift’s.

Switch to the stock Apple profile in System Settings → Displays → Color Profile and check if Night Shift starts behaving normally.

True Tone interaction

True Tone and Night Shift are separate features but they can mask each other.

True Tone constantly adjusts the white point based on ambient light. If True Tone is making the display warm because you’re in warm room lighting, you might not notice Night Shift kicking in on top of that — or you might think Night Shift is broken because the display is warm at noon (it’s actually True Tone responding to your tungsten lamp).

Test: turn off True Tone (System Settings → Displays) and check if Night Shift engages on schedule. If it does, both are working — they were just stacking in a confusing way.

Reset display preferences

If Night Shift settings won’t save, won’t engage, or behave erratically, the display preference files may be corrupted.

Files involved:

• ~/Library/Preferences/com.apple.CoreBrightness.plist — Night Shift specifically lives here
• ~/Library/Preferences/ByHost/com.apple.CoreBrightness.<UUID>.plist
• ~/Library/Preferences/ByHost/com.apple.windowserver.*.plist

Manual cleanup: quit System Settings, Finder → Cmd + Shift + G → ~/Library/Preferences/, find files matching com.apple.CoreBrightness* and com.apple.windowserver*, move to Desktop, restart.

Re-set your Night Shift preferences after restart. If they now stick and Night Shift engages correctly, the prefs were corrupted.

Skip the manual huntSweep clears the cached configs and broken plists that mess with macOS. Download Sweep free →

External display behavior

Night Shift on external displays is more limited than on built-in:

• Apple displays (Studio Display, Pro Display XDR): full support.
• Most third-party HDMI/DisplayPort monitors: Night Shift applies through the GPU’s color pipeline, which works.
• Some monitors with their own color processing: Night Shift can be partially overridden by the monitor’s internal color modes. Check the monitor’s OSD for “Picture Mode” or “Color Preset” — if it’s set to “User” or “Standard,” Night Shift will work normally. If it’s set to “sRGB” or a calibrated mode, the monitor may override the Mac’s color shift.

If Night Shift looks much subtler on an external than on built-in, that’s probably what’s happening.

Apple Silicon vs. Intel

Both architectures handle Night Shift through the Mac’s GPU color pipeline, so the user experience is the same. Where they differ:

• Apple Silicon Macs apply Night Shift more uniformly across multiple displays and don’t have the graphics-switching glitches that occasionally cause Night Shift to pause on Intel Macs with discrete GPUs.
• Intel Macs with discrete GPUs sometimes show Night Shift drop out for a few seconds when the system swaps between integrated and discrete GPU. Disable automatic graphics switching (System Settings → Battery → Options) if this is happening.

Check Focus modes

Some Focus modes can suppress Night Shift. System Settings → Focus → click each enabled Focus → look for “Display” or “Visual” options. Custom Focuses can have rules that disable Night Shift during their active hours.

Sleep Focus on macOS Sequoia, for example, has options that interact with display behavior. If Night Shift won’t engage during specific hours that match a Focus schedule, that’s likely the cause.

Quick sanity check

If everything seems configured right but Night Shift just won’t engage, try this:

• System Settings → Displays → Night Shift.
• Set Schedule to “Custom.”
• Set Custom From “1:00 AM” to “11:59 PM” (essentially always-on).
• Set Color Temperature slider to maximum warmth.

If the display goes obviously warm immediately, Night Shift is working — your previous configuration was the issue. If the display doesn’t shift at all even at max warmth, the system isn’t actually engaging Night Shift, which points to the prefs corruption above.

What Sweep handles

Sweep is a Mac cleaning tool. For Night Shift issues:

• Clears corrupted CoreBrightness and display preference files that prevent settings from saving.
• Wipes cached display state from old peripheral configurations that can interfere with Night Shift on external displays.

Sweep can’t change Location Services or pick a Focus mode for you — those are user settings. For prefs corruption, it’s faster than manually finding and moving plist files.

There’s a faster waySweep does this cleanup in seconds. Try Sweep free →

Check the schedule first. Confirm Location Services is on for sunset/sunrise. Test with Custom and a manual time range. If settings won’t save or Night Shift won’t engage at all, reset display preferences. Most cases get sorted in the schedule and location services checks.