Electronic trip unit for circuit breakers

An electronic trip unit for a circuit breaker is disclosed. The electronic trip unit has a processing circuit, and a real time clock circuit that is operational in the absence of current in the circuit breaker. The processing circuit is responsive to input signals representative of a current in the circuit breaker, and the real time clock circuit is in signal communication with the processing circuit. In response to an off event at the circuit breaker following a current flow condition thereat, the real time clock circuit is configured to generate time information relating to the circuit breaker being off as a result of the off event for use by the processing circuit.