new era; new epoch
Refers to the beginning of a new historical period, often with a sense of significant change or innovation.
この発明は科学の新紀元を開いた。
This invention opened a new era in science.
It was an event that marked a new epoch.
Compound of 新 (new) and 紀元 (era, epoch). The exact historical derivation is uncertain, but the word is conventionally associated with the beginning of a new calendar or historical period.