This work presents a physical theory of time based on canonical global order rather than synchronized clocks, spacetime coordinates, or metric postulates. Time is introduced as an operationally constructed physical parameter, derived from observer-side reconstruction of temporal order using distributed reception of repeatable signals. The theory starts from the premise that intrinsic source-side temporal order is physically inaccessible; only the order of reception events registered by observers is admissible for the construction of time. A canonical global order is reconstructed from distributed reception sequences and shown to be invariant under signal delay, reordering, spatial separation, and dynamic expansion of observational infrastructure. On top of this order, a global operational time parameter is defined as a monotonic accumulation over reconstructed order increments. This time exists only at the observer and does not presuppose simultaneity, intrinsic source time, or a pre-existing spacetime temporal coordinate. A central result of the theory is the immutability of reconstructed temporal history. While observational access may expand through additional sources or reception nodes, such extensions can affect only future reconstruction. Past temporal order and assigned time values cannot be retroactively modified. This non-reconstructibility of history is shown to be a necessary condition for time to function as a causal and coordinative physical quantity. The theory is compatible with the empirical content of Special and General Relativity, but is logically prior to them. Canonical global order is taken as a pre-metric physical primitive, upon which spacetime metrics, relativistic causal structure, and clock models are imposed as secondary representations. Metric time remains applicable to local dynamics, while global operational time provides a physically realizable ordering structure for large-scale coordination. The predictive content of the theory is structural and history-dynamical. It constrains the admissible behavior of time itself, forbidding observer-dependent divergence of global time within a shared reconstruction domain, excluding retroactive modification of temporal history, and predicting convergence of independently reconstructed times across observers. In the asymptotic limit of increasing observational coverage, reconstructed global time approaches a universal ordering structure not as a postulated absolute entity, but as a limit of physically realizable reconstruction.
Alexey A. Nekludoff (Mon,) studied this question.