# Natal Twelfth-Parts Admission **Verdict: admit.** **6.3.0 placement:** new atom + REST; optional profile overlay later. ## Object The Hellenistic dodekatemorion of an ecliptic longitude. Each 30° sign is cut into twelve equal 2°30′ slices. The ordinary natal projection is: projected = (sign_start + 12 × degree_in_sign) mod 360 Seams are left-closed, right-open: `[0, 2.5)`, `[2.5, 5)`, …, `[27.5, 30)`. ## Sources - Ptolemy, *Tetrabiblos* I.22 - Vettius Valens, *Anthologies* (Riley), multiple uses of twelfth-parts - Dorotheus, *Carmen* I.8 - Firmicus Maternus, *Mathesis* II.17 - Skyscript / Wikipedia statement of the 12× formula (Capricorn 17° → Cancer 24°) ## Not this object - Vedic Dwadashamsa / D12 starting-sign variants - Abu Ma'shar Nine Parts - Sahl/Dorotheus electional “malefic in the Moon’s twelfth-part sign” - Chaldean faces (10°) and triplicity decans ## Fail-closed Non-finite longitude raises. Degree 30.0 of a sign does not occur after normalization (`longitude % 360`, then `// 30`).