In 1950 at age eight, prompted by an issue of Life magazine marking the century's midpoint, Stephen Jay Gould started thinking about the approaching turn of the millennium. In this beautiful inquiry into time and its milestones, he shares his interest and insights with his readers. Refreshingly reasoned, erudite, and absorbing, the book asks and answers the three major questions that define the approaching calendrical event.

First, what exactly is this concept of a millennium and how has its meaning shifted? How did the name for a future thousand-year reign of Christ on earth get transferred to the passage of a secular period of a thousand years in current human history?

When does the new millennium begin: January 1, 2000, or January 1, 2001? (Although seemingly trivial, the debate over this issue tells an intriguing story about the cultural history of the twentieth century.) Finally, why must our calendars be so complex, leading to our search for arbitrary regularity, including a fascination with millennia?