Time as a noumenon

This work is dedicated to epistemological analysis of time as a noumenon. It is shown, that positive sciences have different definitions of ontological features of time, and that some essential features of time can only be logically deduced from the needs of physical theories nowadays, not empirically determined. Some properties of time declared by modern science, in principle do not lend themselves to the divine cognition, including industrial and appliance. It’s connected with the features of nature of time, which never openly presents itself, but does it indirectly through changing of subjects and states, partly with the speculativeness of modern theoretical physics. It is confirmed, that different physical theories diametrically disagree in definitions of such features of time like continuity (discontinuity), irreversibility (reversibility), primacy (emergence), dimensionality (multidimensionality). Humanitarian research of time also attribute different and sometimes contradictory features to it. Uncertainty and multiplicity of philosophical and natural-scientific ideas allow putting a question about its principal knowability. The time is not a phenomenon, in principle, and it is not about quite specific properties amenable practical technical knowledge. An appeal to positions of Kant’s theory of knowledge allows to determine time as a positive noumenon in Kantian sense and as something that exists in reality and has quite certain ontology, but hides its genuine ontological features from a cognizer.