The clock is based on a project in 2015 that started out with only one module:
https://www.thingiverse.com/thing:880429

Later in the process we put six modules together to create a clock. We have spent a lot of thought on how to program the controller. The clock has a Cortex M0 controller by STM (STM32F072) with RTC. We employed Basic and modified it especially for PWM LEDs (neopixel). It controls all of the functions except for the autonomous functions in the BIOS like multiplexing, RTC, DCF77, and Basic. Learning how to use this modified version of Basic is easy.