tidsskille

Tidsskille, literally time boundary, is a term used in Norwegian and Swedish to denote a point or boundary in time that separates one period from another. Etymology: tid means time and skille means separation or distinction. The expression is employed across disciplines to signal a significant temporal demarcation rather than a precise date.

In history and historiography, tidsskille describes a turning point or watershed moment that scholars view as a change in conditions, institutions, or economic structures. In calendar and chronology discussions, it can refer to a shift in era, such as the adoption of a new calendar system. In cultural studies, tidsskille may mark the transition between different social or cultural epochs.

In statistics and data analysis, the term is used more loosely to describe a structural break or change-point in a time series, where the statistical properties change markedly at a certain date. In such contexts, identifying a tidsskille helps interpret shifts in trends, means, or variance.

Examples often cited as tidsskille include the industrial revolution as a turning point in economic development, or the transition from a Julian to a Gregorian calendar as a major chronological shift in Europe. Usage notes: the term is not a formally standardized technical term in English-language scholarship; its precise meaning depends on context and language. It is commonly used in Scandinavian discourse to convey a sense of turning point or boundary in time. See also chronology, change-point, era.