Ds1302-Real-Time-Clock-Module-With-Battery-Cr2032-2-Pcs-Whadda-WPI301-p-The-Whadda-WPI1301-DS1302-trickle-charge-timekeeping-chip-contains-a-real-time-clock-calendar-and-31-bytes-of-static-RAM-p-p-It-communicates-with-a-microprocessor-via-a-simple-serial-interface-The-real-time-clock-calendar-provides-seconds-minutes-hours-day-date-month-and-year-information-The-end-of-the-month-date-is-automatically-adjusted-for-months-with-fewer-than-31-days-including-corrections-for-leap