PCF8563 RTC Board (WS-PCF8563) Waveshare
The PCF8563 RTC Board provides the real-time clock/calendar function, which can be driven by a battery on board and works independently even when the MCU is turned off.
The PCF8563 RTC Board features I2C pinheader on one side, and I2C connector on the opposite side. Hence, it's more flexible to connect the board to your development system. The board also supports I2C cascading, allowing the use of multi module connected to the I2C bus at the same time by connecting the pinheader and connector.
PCF8563, I2C pinheader, I2C connector, 3.3V battery included
Development resources: demo codes, schematic, datasheets, etc.