Abstract: A time registering electric energy meter for measuring usage of an AC energy quantity includes primary and secondary DC power supplies and a microprocessor, having a realtime clock maintained by the 60 Hz AC energy quantity, for maintaining realtime and for generating AC energy usage information determined by a number of time-related events. The meter further includes power outage recovery circuitry for measuring the duration of an outage of the AC energy quantity and for restoring the amount of lost realtime to the realtime clock of the microprocessor upon resumption of the AC energy quantity. The power outage recovery circuitry includes apparatus for iteratively updating the microprocessor realtime clock while comparing the updated realtime with the clock calendar times of the number of time-related events to account for the occurrence of such events during the outage of the AC energy quantity.