Abstract
<p>We develop a framework based on maximal spatiotemporal symmetry in which time is promoted to an on-shell three-dimensional vector subspace. Requiring admissible inertial transformations to remain continuously connected to the identity while preserving the common temporal and spatial orientations uniquely selects a pseudo-Euclidean $(3,3)$ signature, rendering the six-dimensional metric interval equivalent to the Lorentzian interval. Compatibility of the temporal-frame transport with this invariant structure fixes the orientation of admissible temporal translation, tying the arrow of time to the preservation of the relativistic interval and preventing the causal pathologies common in multi-time theories. The temporal frame nevertheless retains a residual rotational degree of freedom about the stabilizer of the causal temporal axis. Motion within this transverse temporal sector is tied to the four-coordinate translational action; calibrating the proportionality between infinitesimal variations of the rotation angle and the action recovers the Planck--De Broglie relations. The same compatibility condition yields the temporal-frame angular-velocity relation, from which we derive a first-order, carrier-representation-independent inhomogeneous transport equation equipped with an intrinsic geometric-source field. In the geometric-source-free branch, this equation recovers the standard Dirac form, while its second-order reduction yields the Klein--Gordon mass-shell equation and the Pauli spin--field coupling without additional assumptions. Thus, phase and spin arise natively from the same six-dimensional transport structure. In the presence of a geometric-source field, this structure provides a native channel through which anomalous magnetic-moment corrections and their non-Abelian analogues appear as finite structural responses of the carrier geometry.</p>