A Human-Centric Lunar Time Zone Framework (LTZ/ULTZ) for Coordinated Lunar Operations

This preprint proposes a human-centric lunar operational time framework built around a Universal Lunar Time Zone (ULTZ) and 24 canonical longitude-based Lunar Time Zones (LTZ). The framework is intentionally geometric and independent of solar illumination. It separates the underlying continuous SI-second reference from a scaled 24-division lunar operational display, allowing machine-level timing precision to coexist with human-readable local lunar time. The paper defines the mathematical mapping from a continuous reference timescale to ULTZ and from selenographic longitude to canonical LTZ identifiers. It also specifies antimeridian handling, zone naming, leap-second continuity policy, conformance rules, and an Adaptive LTZ (ALTZ) layer for future base-specific operational conventions. Additional extensions include a Lunar Time Core (LTC) for lunar-resident timing autonomy, a Lunar Illumination Index (LII) as separate environmental metadata, and a governance model for future multi-stakeholder standardization. A staged validation programme is proposed covering software verification, human-factors testing, networked rover/base testbeds, and mission-integration studies. The framework is positioned as an operational and civil-style representation layer that complements, rather than replaces, precision timing standards, relativistic corrections, spacecraft clock systems, or future internationally adopted lunar reference-time architectures.