Ante Christum natum
（重定向自Ante Christum）
The term ante Christus natum (Latin for before Christ (was) born), usually abbreviated to a. Chr. n., a.Ch.n., a.C.n., A.C.N., or ACN, denotes the years before the birth of Jesus. It is a Latin equivalent to the English term "BC" ("before Christ"). The phrase ante Christum natum is also seen shortened to ante Christum (Latin for "before Christ"), similarly abbreviated to a. Chr., A.C. or AC. A related term, p. Chr. n., p.Ch.n, or post Christum natum complements a.Ch.n and is equivalent to "AD".