DS1307 RTC MODULE W/O BATTERY DS1307

This Tiny RTC Real Time Clock DS1307 I2C Module is a real-time clock IC with a backup battery that can be used with Arduino.  It’s one of the easiest to use RTCs out there, with Arduino and other libraries or simply use I2C commands to set and retrieve the time and date. 

Along with the DS1307 real-time clock, the module also has an Atmel 24C32 EEPROM chip, for storing data. There is also space on the board for the DS18B20 temperature sensor. 

RTC DS1307 clock allows you to keep a reasonably accurate time even when your Arduino is powered off, thus very helpful in data logging and other time-sensitive applications.