The current crises of modern societies—ranging from political incapacity to act, through the reproducibility crisis in science, to the simulation of responsibility in administration and AI—cannot be adequately understood as mere problems of programs, morality, or governance. They point to a deeper deficit: an inadequate ontology of time.Starting from the dominance of block-time models in physics, philosophy of science, and political practice, this paper develops the concept of Eigenzeit as a categorical alternative. Eigenzeit denotes the non-delegable instantiation of world-time in human action, in which decision, responsibility, and irreversible world-binding are inseparably intertwined. Time thus appears not as a given dimension or measurable duration, but as the effect of irreversible closures in structurally incomplete worlds.In contrast to block time, probabilistic models of freedom, and information-ontological approaches (e.g., simulation, “It from Bit”), decision is not understood as a selective or aggregative act, but as an ontologically binding set-point. This entails fundamental consequences: reproducibility proves to be a criterion of closed world-forms; politics proves structurally incapable of deciding Eigenzeit collectively; and human and fundamental rights prove insufficient insofar as they implicitly address the human being without protected Eigenzeit as an object.Eigenzeit is thus not proposed as another model of time, but as a necessary ontological category for irreversible, non-simulable world-conditions, and as the foundation of a theory of societal reality formation beyond administration, simulation, and symbolic politics.