[DEC-2] Time as the Irreversible Closure of Possibilities

Time is commonly treated as a fundamental parameter ordering physical events or as a background dimension within which dynamics unfold. This paper proposes an alternative, non-substantival conception: time is defined as the irreversible closure of possibilities. Rather than flowing independently of physical processes, time emerges from the progressive elimination of alternative futures physically admissible from a given state. Irreversibility is not a secondary feature of time but its constitutive condition. By grounding temporal asymmetry in constraint evolution rather than metric change, this framework provides a unified account of the arrow of time and the distinction betwe en past, present, and future. The proposal is compatible with existing physical theories and avoids circularity by defining temporal order through structural exclusion rather than presupposed temporal notions.