This project started with an old nixie tube display rack and an Arduino mega 2560 with DS1307 RTC. The nixies are driven with the SN74141 BCD to nixie drivers. This project was a lot of fun to build it also has a temperature and humidity sensor DHT11.
RTC_Module_S_M_H_1HZ_Interrupt_newAMPM_newPin_SC_adj_TH_working.txt