beforecommon

Beforecommon is a term that appears in discussions of chronology to denote time preceding the start of the Common Era (CE). In a neutral or non-religious dating framework, it can function as an era label similar in purpose to BCE or BC, but its exact meaning is defined by the conventions of a particular project, publication, or data schema. Because it is not widely standardized, documentation accompanying its use specifies how years are counted and mapped to other era systems.

Usage of beforecommon tends to be limited to niche contexts such as historical databases, academic datasets, or fictional worlds where a non-religious dating vocabulary is preferred. Proponents cite advantages in avoiding religious terminology, while critics note the lack of universal agreement and potential for confusion with established systems.

Practical considerations for implementing beforecommon include deciding whether a year zero exists, how to map values to conventional BCE/BC or astronomical year numbering, and how to handle leap years in a calendar model. Any conversion to or from BCE/BC, CE, or AD should be explicitly documented to prevent misinterpretation. In datasets, beforecommon values are typically documented with an anchor year or epoch to provide a clear reference point.

Examples of usage are hypothetical, with a dataset stating events as beforecommon 500 or beforecommon 1200, accompanied by a note defining the chosen epoch and any conversion rules. Etymologically, the term is a coinage pairing before with common, signaling its intended role as the pre-Common Era counterpart. See also Common Era, BCE/BC, BC, BCE, astronomical year numbering.