CNC_UAT - Operational Detection of Silent Gauge Transformations: A 3ns Anomaly in the UTC Network.

The integrity of high-precision time distribution relies on the assumption that administrative metadata (Calibration IDs) accurately reflects the physical state of the network. We demonstrate that this assumption is insufficient for ensuring micro-scale synchronicity. Using a preregistered "Holonomy Witness" protocol—which audits the topological closure of time differences across independent measurement gauges (TWSTFT vs. GPS PPP)—we isolate a statistically significant gauge discontinuity in the operational UTC network. Specifically, we detect a +2.99 ns step-function anomaly in the NPL-PTB baseline on December 9, 2024 (MJD 60653). Crucially, this discontinuity occurred while the official BIPM Circular T metadata reported a stable Calibration ID (0620-2024) and measurement type (TWGPPP), constituting a "silent" gauge transformation. While global reference frames (NIST, OP, IT) exhibited a correlated 1-2 ns shift on September 30 consistent with a coordinate update, the NPL event was baseline-unique, empirically validating the existence of Local Gauge Freedom in macroscopic clock networks. We map this failure to a "Loop Defect" in the Hamiltonian constraint algebra and propose the Holonomy Witness as a necessary, metadata-agnostic audit layer for distributed quantum and classical timing arrays. What’s included in this record: silent_gauge_operational_networks_v1_1.pdf silent_gauge_operational_networks_v1_1.tex CNC_SilentGauge_EvidencePack_v1.0.0_2026-01-02.zip (tables/figures/manifests supporting Table 1 / Fig 1) Reproducibility note: Evidence pack is derived products + plots; upstream operational link files are from BIPM (webtai) and are cited; code is at Zenodo 18101933. Integrity: SHA-256 manifest included; evidence pack hash printed in the paper.