Grove - DS1307 RTC (Real Time Clock) for Arduino

An RTC (Real Time Clock) is a clock that keeps track of the current time and can be used to program actions at a specific time.Arduino and almost all microcontrollers have built-in timers that can run as long as there is power. However, as soon as the power is turned off (either manually or due to a power failure), all timers are reset to 0. It is acceptable to use the internal timer for timing simple projects if you don't mind the timer resetting to zero when the power is turned off. But for projects such as data loggers, clocks, alarms, where the timer needs to run independently of the external power supply, you need to use an RTC. Almost all RTCs are low power integrated ICs and can run for many years on a single lithium battery. At present, the RTC based on the DS1307 real-time clock is one of the most popular RTC modules.