nightglow

Free & open source · Apache 2.0 · macOS 13+

Nightglow

Your Mac, in step with the sun. Full daylight while it's up; warm, gentle light once it sets, on every display you own.

Download for Mac Read the source
Place
San Francisco
37.8° N 122.4° W · default
Sun
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Sunrise · Sunset
— · —
This page
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Local time
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I · The day

This page is already running Nightglow.

The colors you're reading come from the sun's position where you are right now, or over San Francisco if you'd rather not share. Drag across the day to see what your screen will do.

Sky at the horizon Your screen's tint and brightness

II · How it works

Follows the sun, not the clock.

  1. 01

    Twilight, measured

    Nightglow computes the sun's elevation for your coordinates with the NOAA solar equations. Daylight holds until the sun is 3° up, then eases to evening warmth by the end of civil twilight, 6° below the horizon. In June and in December, in Oslo and in Quito, it tracks the real sky.

  2. 02

    Every display, calibration intact

    It scales each monitor's own ColorSync gamma table rather than replacing it. External screens warm up too, and your calibration survives.

  3. 03

    Works before you say yes

    No location permission? Nightglow starts from your time zone's reference city. Allow Location Services and it refines to within a kilometre. Coordinates never leave your Mac.

  4. 04

    Can't leave you orange

    macOS drops the tint the moment the app quits or crashes. Pause for an hour from the menu, preview a whole day in twelve seconds, or set day and night temperatures from Candle to Daylight.

Nightglow's menu: 3400 K at night, sun elevation, next sunrise, pause and preview controls
The menu bar, after sunset.
Nightglow settings: day and night temperature and brightness sliders, location source, launch at login
Settings: temperatures, brightness, location.

III · Install

Two minutes, then forget it.

  1. Download

    Get Nightglow.zip, unzip it, and move Nightglow.app to Applications.

  2. Open it once

    Nightglow isn't notarized yet, so macOS asks first. Open it, then choose System Settings → Privacy & Security → Open Anyway. Or run: 

    xattr -dr com.apple.quarantine /Applications/Nightglow.app

  3. Or build it yourself

    git clone https://github.com/micahstubbs/nightglow
cd nightglow && yarn install-app

    Swift, no Xcode project, 23 tests. Pull requests welcome.