valens-decennials-1.0.0 is a deterministic TypeScript chronology over immutable saved natal longitudes and the exact stored Julian-day epoch. It does not call the ephemeris again and does not alter natal facts.

Source rule

In Anthologies Book VI §6.6, Valens assigns 10 years and 9 months to each major chronocrator and advances through the planets as they are situated by sign and degree in the nativity. The subordinate month counts are Saturn 30, Jupiter 12, Mars 15, Sun 19, Venus 8, Mercury 20, and Moon 25; their sum is 129.

Apheta policy

The source asks for the Sun in day births or Moon in night births if well situated, and gives the planet following the Ascendant when both lights are badly situated. The controlling-point material is qualitative and configuration-sensitive. Version 1 therefore defaults the interface to the sect-luminary convention but exposes three named policies and records the actual selected planet. It does not claim to solve or certify the broader apheta judgment.

Exact algorithm

• Validate exactly one finite longitude for each traditional planet.
• Normalize all longitudes into [0, 360).
• Place the selected apheta first, then sort the remaining planets by increasing zodiacal distance from it.
• Break exact-longitude ties with the stable order Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn.
• Assign each successive major lord 129 × 30 exact days from the stored birth epoch.
• Inside a major period, rotate the same natal order to begin with its major lord.
• Advance the subordinate UTC cursor by each lord’s source month count × 30 exact days.
• Locate the active major and subordinate periods with start-inclusive, end-exclusive boundaries.

Regression coverage

• The seven planetary month values total 129.
• Every major period lasts exactly 3,870 days.
• Every set of seven subordinate periods exactly meets its major boundary.
• A day chart recommends the Sun and a night chart recommends the Moon.
• The Ascendant-follower calculation wraps correctly through 0° Aries.
• A selected apheta remains first during an exact-longitude tie.
• An exact subordinate boundary belongs to the newly beginning lord.
• Missing, duplicate, unknown, or non-finite planetary records fail closed.

Version 1 exclusions

Valens also discusses smaller daily and hourly subdivisions and qualitative transmitter-receiver judgment. Those layers require their own source and interpretation contracts. Version 1 publishes only the major and monthly chronology, selection provenance, and natal order.