About

Matthew Ball

I build Abendrot, a free, open-source macOS app that warms your screen’s color temperature across every display — including the external monitors where Night Shift stops.

Why I built Abendrot

I wanted warmer screens at night on every display I use, not just the built-in laptop panel. The existing options either skipped external monitors or did more than I needed, so I built a small, dedicated Mac app that does one thing well. It is free, open source under the MIT license, and collects zero telemetry.

Why this blog exists

Circadian Notes are practical, source-checked guides on screen warmth, blue-light filters, and circadian-friendly computing. Every claim links back to a primary source — platform documentation, lighting references, or public-health guidance — so you can check the reasoning yourself. It is written as general wellness information, not medical advice.

Find me

I’m on GitHub at github.com/matthewrball, and Abendrot’s source lives in the abendrot repository. If you spot something wrong in a guide, open an issue — corrections are welcome.