Year zero
Historians have never included a year zero. This means that between, for example, and , there are 999 years: 500 years BC, and 499 years AD preceding 500. In common usage "anno Domini" 1 is preceded by the year 1 BC, without an intervening year zero. Neither the choice of calendar system (whether Julian or Gregorian) nor the era ("Anno Domini" or Common Era) determines whether a year zero will be used. If writers do not use the convention of their group (historians or astronomers), they must explicitly state whether they include a year 0 in their count of years, otherwise their historical dates will be misunderstood.
Zero: The Biography of a Dangerous Idea
Zero: The Biography of a Dangerous Idea is a book by American author and journalist Charles Seife. The book offers a comprehensive look at number 0 and its controversing role as one of the great paradoxes of human thought and history since its invention by the ancient Babylonians. Even though zero is a fundamental idea for the modern science, initially the notion of a complete absence got a largely negative, sometimes hostile, treatment by the Western world and Greco-Roman philosophy. "Zero" won 2001 PEN/Martha Albrand Award for First Nonfiction Book.