About

Matthew Ball

I build Abendrot, a free, open-source macOS app that warms each display using the methods available on that Mac, with a screen-tint fallback when direct warming is unavailable.

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 the Mac app sends no 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.