The sun is up, so is your screen.
Sunrise and sunset are computed on your Mac from your location. Shift each one by up to two hours, or pick fixed times if you prefer a routine to the sky.
Grey sky, dark day.
The first forecast of the morning decides. When clouds cover the sky or a storm is coming, the whole day stays dark, without flipping back and forth at each update.
Or ask the room.
Connect a light sensor from Home Assistant and let the actual brightness around you choose. Two thresholds and a short delay keep a passing cloud from switching anything.
Sunset changes everything at once.
Dark mode turns on and your night wallpaper takes over on every display. Changed your mind? ⌃⌥⌘D flips it until the next scheduled change.
Then the screen warms up.
Colour temperature slides slowly from daylight to the warmth you chose, down to candlelight. Night Shift steps aside so the two filters never stack, and everything returns to neutral after sunrise.
6500 K to 1900 KOne pane per idea.
Everything lives in the menu bar. Settings open in a single window, light or dark like the rest of your Mac.
Schedule Sun, fixed times or manual 
Weather Cloud threshold for dark days 
Home Assistant Server, token and lux sensor 
Wallpapers One for the day, one for the night 
Evening warmth Start time, target and rendering 
General Shortcuts and launch at login
Nothing leaves your Mac
No account, no analytics. Only the weather, if you turn it on, sends a location rounded to about a kilometre to Open-Meteo.
First launch
Builds are not notarized yet. If macOS refuses to open the app, click Open Anyway in System Settings › Privacy & Security.
Keep it going
The code is on GitHub. If the app is kind to your eyes, you can sponsor its development.
Sponsor on GitHub