Era

An era is a span of time defined for the purposes of chronology or historiography, as in the regnal eras in the history of a given monarchy, a calendar era used for a given calendar, or the geological eras defined for the history of Earth. Comparable terms are Epoch, age, period, saeculum, aeon (Greek aion) and yuga (Sanskrit युग).

Extends: Chronology, [Units of time](https://wikipedia.org.ai/Units of time)