The build consists of a Raspberry Pi Pico that connects to a DS3231 real time clock (RTC) with a Waveshare 3.7 inch eInk display which [Dmytro] puts into a custom 3D printed case. The RTC has it ...

The build relies on an Arduino Pro Mini to run the show, paired with a DS3231 real-time clock module. The latter part is of great importance, as without it, the Arduino would not keep accurate time.