Abendrot is a free, open-source Mac screen warmer that cuts nighttime blue light. It warms every display around your local sunset so your evenings aren't lit up like daytime. At night, you need to reduce your blue light exposure. Abendrot targets the root cause of sleep disruption by minimizing the specific short-wavelength, melanopic light (blue/cyan) that tricks your body clock into thinking it's still daytime. Warmth is a spectral edit of the display, not a clinical treatment or a sleep-outcome guarantee. Per-display warmth including external monitors, menu bar app with a scriptable CLI, no account, no telemetry.
I built Abendrot because Night Shift and f.lux often go quiet on external monitors and buttonless Apple displays. I wanted a free MIT-licensed menu-bar warmer that actually hits every screen around local sunset and names the method per display.