Big Precision Clocks

These clocks are synchronised via GPS, and display local time (currently BST, or UTC+1) to the nearest millisecond. There is an onboard world atlas and timezone database, so if you carry a clock to a different timezone, it automatically updates.

Their display follows the "one true date format", known as ISO8601. Even when filmed with a high-speed camera, the displays do not flicker.

I gave a talk at EMF2024 about the development of these clocks, it's available to watch here: https://media.ccc.de/v/emf2024-337-gps-time-leap-seconds-and-a-clock-thats-always-right

There's also an unsettlingly long writeup on my website: https://mitxela.com/projects/precision_clock_mk_iv