In cognitive linguistics, a widely accepted and highly influential approach to the notion of time is conceptual metaphor. This states that the abstract concept time should be understood in terms of a concrete concept such as space. This paper challenges this notion by proposing that time exhibits independent experience. Using diachronic data, the paper investigates how temporal expressions in Japanese have emerged that are also employed as spatial expressions, and demonstrates how they conform to theoretical standpoints that are postulated in synchronic studies. First, I refer to the insights of Fraisse (1963), who singles out from a psychological point of view two fundamental perspectives of time: succession and duration. Second, I provide 10 examples from the eighth century to the fourteenth century that comply with five aspects of psychological reality (succession, duration, causation, organization, and anticipation). Third, I evaluate Evans' (2004) cognitive complex models that champion temporal independence. The paper makes two claims. First, the rise of Japanese temporal expressions does not rely on external experience but on internal, that is, psychological perspectives. Second, the three attributes central to Evans' models (motion, agency, and sequence) were not absolutely fundamental when Japanese temporal expressions emerged. While this last point downgrades Evans' models, the paper tentatively suggests an alternative approach, namely that a diachronic development should embrace indexical, iconic, and symbolic evidence for the construction of linguistic signs.