Used in technical, historical, or computing contexts to refer to a distinct period or a reference point in time. Common in phrases like エポックメーキング (epoch-making).
This invention marked a new epoch in science.
UNIX時間のエポックは1970年1月1日です。
The Unix epoch is January 1, 1970.
This invention marked a new epoch in the history of science.
That technology opened up a new epoch in the information society.