This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
The planetary hour system an entry describes did not originate with any single grimoire or Renaissance textbook. Nicholas Campion's documented history traces the Chaldean ordering of the seven classical planets, and the twenty four hour division it generates, back to Hellenistic astrology, itself building on earlier Mesopotamian planetary sequences, well over a thousand years before Lilly's own seventeenth century English handbook restated the system for a working astrologer of his period.
That long, documented chain of transmission matters for how an entry is written, since the system reached the Latin West by way of a specific, traceable path, Hellenistic Greek astrology into Arabic astrological writing and from there into medieval and Renaissance Latin and vernacular texts, and Campion's history records where each stage of that transmission preserved the original Chaldean order intact and where a later writer's own restatement introduced a variation.
An entry draws on this documented history for the system's origin and transmission, keeping that historical record distinct from any single period's own practical handbook, which states how the system was used at one particular moment rather than where it came from.