BC

   , BCE

   abbreviations for "before Christ" and "before common era," respectively.

   These are standard designations for years before the beginning of the common or Christian era (see CE). Oddly, there is no year designated 0 in the common system for numbering years; the year 1 CE (or 1 AD) was preceded by 1 BCE (or 1 BC). The lack of a year 0 means that the number of years elapsing between the year n BCE and the year m CE (or n BC and m AD) is n + m - 1.