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.
Numbers in Year Zero
This is a comprehensive list of the numbers of the Year Zero alternate reality game by Nine Inch Nails and 42 Entertainment. The "Year Zero" alternate reality game, and its accompanying concept album of the same name, criticizes the United States government's policies as of 2007, projecting a dystopian vision of its impact on the state of events in 2022. The game has been underway since roughly February 12, 2007 and is expected to continue for approximately eighteen months.