TL;DR - A simple mission to write a guide for some people on Reddit on how to create a plane spotting screen led me down a deep ADS-B rabbit hole and ended with me building a clock.

Read on for a guide to build a screen yourself (GitHub repo here), or if you can't be bothered to source the components and run your own ADS-B station, I can send you a kit with everything you need to set up a clock like the one above.