What Is a Real Time Clock, real-time clock chip, rtc real time clock

 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