You can add a real-time-clock circuit if you want it precise. ... 23 thoughts on “ Simple Clock Is Great Stepper Motor Project ” TheGuv says: July 21, 2016 at 1:37 am ...

Additional PCBs hold an Arduino Mega 2560 that runs the whole show, a DS3231 real-time clock for accurate time-keeping, and a power supply to manage the 40-odd watts consumed by the display.