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 colour of an ordinary light bulb, still heavy in the 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 well past anything in System Settings. Brightness dimming works by pulling the gamma curve down rather than leaning on the backlight, so the screen goes darker at night without adding flicker. Media keys keep working, and a smooth ramp engine makes every transition glide.
The science behind display colour temperature and melatonin is real and cited: Sundown's science page (trysundown.com/science) walks through 14 primary papers, including the randomised-trial evidence, and is honest about what the research does and does not show.
Sundown is native Swift (no Electron, ~6 MB download), requires no account, and ships regular releases. macOS 14+, 7-day free trial.
