DS1307 Real Time Clock module is used to track the current time and date. It is generally used in computers, laptops, mobiles, embedded system applications devices etc. In many embedded system, we need to put time stamp while logging data i.e. sensor values, GPS coordinates etc. For getting timestamp, we need to use RTC (Real Time Clock).This module is based on the DS1307 IC from Dallas. It uses a 32.768 KHz clock. And supports I2C Interface.SpecificationsDS1307 I2C real-time clock chip (RTC)AT24C32 32K I2C EEPROM memory56 Bytes of Non-volatile memory available to user.Supply voltage 4.5-5.2VBattery voltage 2.0-3.5VTwo wire I2C interface.1Hz output pin.AT24C32 32K I2C EEPROM memory.56 Bytes of Non-volatile memory available to user.Two wire I2C interface.