Temporal Authority in Digital Records: Publicness, Canonical Identity, and Institutional Validation

Digital systems often collapse measurement (clock behavior), convention (UTC/civil regimes), and interpretation (human renderings) into one timestamp. Under heterogeneity and adversaries, this collapse becomes unstable: parsers diverge, regimes change (DST), and correction layers improve over time. This paper targets a narrow question: when does a temporal claim become usable in disputes between parties who do not share trust? We call that status temporal authority, and define it as public verifiability under published rules. We introduce CANON/PROJECTION to separate (i) canonical identity and audit commitments (CANON) from (ii) interpretive renderings and correction regimes (PROJECTION). Three theses are stated as constraints on a minimal model: T1 (Non‑Contamination), T2 (Admissibility Gate), and T3 (Authority as Public Verifiability). We apply the same criteria comparatively to ISO/IEC 18014, RFC 3161, and Merkle time‑stamping, and only then to KDS‑UTI (Škondrić, 2026). Public test vectors with full canonical strings and SHA‑256 digests are embedded to enable independent replication.