Real time clock module, real time clock applications, What Is a Real Time Clock - tatanh1983/conchodom GitHub Wiki
PCF85263ATL/AX PCF85263A Series 5.5 V Tiny Real-Time Clock/Calendar - DFN2626-10
https://www.futureelectronics.com/p/semiconductors--real-time-clocks/pcf85263atl-ax-nxp-9072128