Sundown

Your Mac ships calibrated for noon. Sundown is a menu-bar app that fixes that for the hours after sunset: it drives the display far warmer and dimmer than Apple's built-in controls allow. Night Shift's warmest setting sits around 2700K — the color of an ordinary light bulb, still heavy in the blue wavelengths that signal "daytime" to your brain. Sundown goes an order of magnitude deeper, down to 500K, a deep candlelight red.

Warmth and brightness run on a sunset-to-sunrise schedule or fully manual control, with six presets — Flow, Reading, Evening, Deep Sleep, Biohacker, Custom — and an intensity range that goes well past anything in System Settings. Brightness dimming works by pulling the gamma curve down rather than leaning on the backlight, so you can take the screen darker at night without adding flicker. Media keys keep working; a smooth ramp engine makes every transition glide.

The science behind display color temperature and melatonin is real and cited: Sundown's science page (trysundown.com/science) walks through 14 primary papers, including the randomized-trial evidence, and is honest about what the research does and doesn't show.

Sundown is native Swift — no Electron, a ~5.8 MB download — requires no account, and is actively maintained with regular releases, in a category where the best-known tool, f.lux, still ships a Mac binary dated 17 May 2023. macOS 14+ (Sonoma or later), Apple Silicon and Intel. $4.99/month, $39/year, or $79 lifetime, with a 7-day free trial.