Temporal Realization Zone: Operational Boundaries of Time in Spacetime

Time has been a central concept in physics, traditionally modeled as a coordinate in space- time, operationally defined by clock readings, and in some approaches, emergent from relational interactions. In this paper, we introduce the Temporal Realization Zone (TRZ), defined as a region of spacetime where time acquires physical meaning only through causal interaction medi- ated by light or equivalent massless carriers. We formalize this concept, compare it to existing theories of time, and propose testable experiments in laboratory, quantum, and astrophysical contexts. This framework provides a unifying operational principle linking relativity, quantum mechanics, and horizon physics, reframing time as a physically realized quantity rather than a purely mathematical coordinate.