Electional astrology
Katarchic astrology — Dorotheus of Sidon, Carmen Astrologicum, Book V (1st c. CE)
Electing the right time to begin something — katarche — is one of the oldest branches, set out in Dorotheus's Book V and carried through the Arabic and medieval traditions. In the Hellenistic period 'katarche' meant electional and inceptional work; extending the word to cover horary questions is a late-20th-century usage.
What it measures
A scan of a date range for moments that satisfy chosen classical criteria — the Moon waxing and not void, Mercury direct, the Moon clear of the malefics, benefics on the angles — reported as pass/fail per rule rather than a single score.
Where practitioners disagree
- Which void-of-course definition gates the search?
No remaining Ptolemaic perfection before ingress (ours) — or Lilly's benefic exception — or the fixed 30° rule
The choice moves the void windows the finder excludes.
This engine: No remaining Ptolemaic perfection to Sun–Saturn before the Moon's next sign ingress.
Sources
- Dorotheus of Sidon, Carmen Astrologicum, Book V (1st c. CE)