The DS1307 is a battery-backed clock/calendar with 56 bytes of SRAM. The clock/calendar displays data in seconds, minutes, hours, days, dates, months, and years. Each month's end date is automatically changed, particularly for months with fewer than 31 days.

They come in the form of integrated circuits (ICs) that control time like a clock and date like a calendar. The key advantage of RTC is that it has a battery backup system that keeps the clock/calendar working even if the power goes out. The RTC requires a tiny amount of electricity to stay active. These RTCs may be found in various applications, including embedded devices and computer motherboards.