same period; same era; contemporary
Refers to the same historical period or era. Often used in contexts comparing people, events, or works from the same time. Can also imply being of the same age when referring to people, but 同い年 is more common for age.
He is a playwright contemporary with Shakespeare.
この二つの作品は同時代に書かれた。
These two works were written in the same period.
He was a writer who lived in the same era as Natsume Soseki.
This painting is very innovative compared to works from the same era.