Real Time Clocks (RTCs) keep track of the current time and date with high accuracy and precision. They operate independently of the main system and are battery-backed to retain timekeeping functionality even during power loss. RTCs typically include features such as calendar alarms, temperature-compensated crystal oscillators (TCXOs) for accurate timekeeping, and programmable clock outputs. They find extensive use in electronic devices requiring time-dependent operations. High-precision RTCs with temperature-compensated oscillators and advanced timekeeping functionalities may have higher price points compared to basic RTCs with standard timekeeping features. When purchasing RTCs, consider the specific requirements of your application. Determine the desired accuracy level (e.g., parts per million), supported clock/calendar functions (e.g., alarms, countdown timers), backup battery support for power loss scenarios, and compatibility with your microcontroller or system interface (e.g., I²C, SPI). Evaluate factors such as operating voltage range, power consumption, and temperature stability for reliable timekeeping performance.