Solarian — Comparative Evaluation of Planetary Calendar Architectures

Solarian — Comparative Evaluation of Planetary Calendar Architectures is an informative, requirements-based comparison of five families of civil-time systems: a common Earth-derived calendar, fully independent local calendars, locally designed calendars with shared chronology, synthetic human-scale years with astronomical overlays, and Solarian’s two-layer shared grammar. It considers ten stated design requirements and six practical settlement and interoperability scenarios, including Mars, Jupiter’s moons, long-period outer worlds, multi-world records and small-body edge cases. The assessment identifies both Solarian’s multi-world structural benefits and circumstances where other arrangements may be preferable. It is a qualitative analysis; no numerical scientific ranking, human-adoption survey or independently certified performance test is claimed. This paper is one of four informative companions to JB Bullock’s separately copyrighted book Solarian: An Operating Calendar for Every Planet (First Public Web Edition 1.0, October 2026), available at https://iamjbcom.github.io/solarian/. The standalone normative Solarian Protocol v1.0 has not been published and remains on technical hold. The 19 asteroid profiles and 61 supplementary candidate forms are not ratified, and comprehensive SPICE/Horizons verification is not claimed. Initial Public Issue 1.0 (October 2026). Original author content © JB Bullock 2026; licensed under Creative Commons Attribution 4.0 International (CC BY 4.0). The license does not extend to the separately copyrighted book or its 32 illustrations, nor to separately identified third-party material. The approved PDF, original Markdown source and individual CC BY 4.0 notice are provided here as separate files. Canonical companion source: https://github.com/iamJBcom/solarian/blob/main/papers/03-comparative-evaluation.md.