时代

The book stays au courant by constant revision.

Other times, other manners.

epoch-making event

primitive/remote times

information era

computer/atomic age

needs of the times

reflect the features of our age

bring/usher in an era

adapt oneself to the times

usher in a new era

enter an era

keep abreast of the times; keep up with the times

be out of step with the times

early in one's childhood

from adolescence upward

school days; one's time as a student

youth

childhood