BC - Abbreviation used in the Polish language, developed "BC ", which indicates the date before the beginning of the Christian era, which is tied to the date of the birth of Jesus Christ. It corresponds to the Latin shortcut AC, or ante Christum or the English BC or BC or before Christ (Engl. "BC "). At the end of the eighteenth century to name the year before the date of the birth of Christ used the abbreviation A.CHr.n. (Ante Christum natum). For the purposes of astronomy, history and dates of all events of this period