REFERENCE
METHODOLOGY
How Electional scores windows: a deterministic, additive, bounded-per-pass engine over Swiss Ephemeris data, with explicit gates and natal-first priority.
What is electional astrology?
Electional astrology is the practice of choosing the most favorable moment to start an action based on the current sky and the actor's birth chart. Distinct from natal astrology (the chart of birth) and horary astrology (the chart of a question asked at a specific moment), electional actively picks the time.
The tradition runs from Dorotheus and Vettius Valens (Hellenistic), through Guido Bonatti (medieval) and William Lilly (17th century), to modern practitioners Chris Brennan, Demetra George, Mary Shea, Ciro Discepolo, and Celeste Teal. Electional draws from all of them.
The 7-pass engine
Pass 1
Sky Strength
Baseline conditions independent of intent: Moon phase, Moon void-of-course, near-eclipse volatility, overall benefic-vs-malefic pressure, Via Combusta cautions, syzygy proximity.
Pass 2
House Match
Topical house-ruler activation. Does the planet ruling the intent's house have favorable aspects? Are angles supported? Is the chart's structural alignment with the intent visible?
Pass 3
Goal Match
Intent-specific significators: the primary planets associated with the intent, support planets, caution planets, and which aspect families the intent prefers (harmonious, mixed, challenging).
Pass 4
Natal Fit
Activation of natal anchors via transits: natal target condition, topical natal occupants, planetary returns, and natal compatibility filters. Annual context (profection and solar return) is reported beside the timing score.
Pass 5
Refinements
Transit-to-transit sky-pattern scoring + advanced traditional cleanup layers (hour ruler, day ruler, mutual reception, etc.).
Pass 6
Solar Return Transits (on by default)
Current transits to the solar-return chart's angles and points, scored with Discepolo's tight orbs. On by default whenever annual context is on; secondary and hard-capped.
Pass 7
Discovery Contacts (optional)
Curated asteroid and fixed-star contacts, scored as minor evidence and only when those finders are on. Hard-capped; never creates a window or overrides a gate.
Gates
A gate caps the final score when fundamentals are wrong. Gates override additive accumulation — you can't pile on supporting aspects to overcome a debilitated primary significator. The documented gates:
- Debilitated primary majority: most of the intent's primary planets are in detriment, fall, or combust at the candidate moment.
- Dark-Moon guard: for building or attracting goals, the last days before New Moon cap the score only when another Moon problem backs it up. Moon phase alone is a small warning, and release work is never gated by phase.
- Chart-tenor contradiction: the chart's overall benefic/malefic balance fights the requested polarity.
- Hostile-sky topical inflation veto: a hostile sky inflates topical hits beyond what the underlying conditions justify.
Annual context (profections + solar returns)
Annual context is capped, receipted background reported beside the timing score. It does not change minute-level totals or ranking, never relocates the natal chart, never creates election windows on its own, and never overrides a gate. Profection advances the natal Ascendant one whole sign per year; the ruler of the profected sign becomes the lord of the year. Solar return chart structure layers in.
Solar return location election is a separate feature with its own bounded scorer (cap 37 points across six passes) for picking the best birthday location given an intent. See /solar-return.
Bands
Scores roll up to a percent of the derived achievable max and a band:
- PRIME ≥ 65% — strongest windows, clear structural support.
- STRONG ≥ 48% — solid windows, good fit with some friction.
- USABLE ≥ 30% — workable windows, mixed signals.
- FRAGILE< 30% — weak or contraindicated.
The achievable max is derived (sum of positive caps), not hand-tuned. This means the band thresholds correspond to genuine structural strength, not arbitrary cutoffs.
Sources
- Chris Brennan — Hellenistic Astrology: The Study of Fate and Fortune
- Demetra George — Ancient Astrology in Theory and Practice
- Mary Fortier Shea — Planets in Solar Returns
- Ciro Discepolo — Transits and Solar Returns (Active Astrology)
- Celeste Teal — Predicting Events with Astrology
- Alexandre Volguine — The Technique of Solar Returns (1937)
- James A. Eshelman — Interpreting Solar Returns
- Guido Bonatti — Liber Astronomiae (electional rules)
- William Lilly — Christian Astrology
- Swiss Ephemeris (Astrodienst) — calculation engine
FAQ
What is electional astrology?
Electional astrology is the practice of choosing the most favorable moment to start an action based on the current sky and the actor's birth chart. It's distinct from natal astrology (the chart of birth) and horary astrology (a chart answering a question asked at a specific moment).
What ephemeris does Electional use?
Swiss Ephemeris (sweph), the same calculation library professional desktop astrology software like Solar Fire uses. Falls back to the Moshier ephemeris when Swiss Ephemeris data files are unavailable, with a warning in the API response.
How does the scoring engine work?
The engine runs 7 sequential passes (sky strength, house match, goal match, natal fit, refinements, solar return transits, discovery contacts). Together they evaluate 40 scoring rules; each pass contributes a bounded number of points, and the totals roll up to a percent score and a band (PRIME, STRONG, USABLE, FRAGILE).
Why bounded scoring instead of raw additive?
Per-pass caps prevent any single signal from dominating a score. Gates (debilitated primary significator, the dark-Moon guard for building goals, chart-tenor contradiction, hostile-sky veto) cap totals when fundamentals are wrong. This produces honest scoring instead of inflated headline numbers.
Are aspects between transiting planets used?
Yes. Transit-to-transit aspects are evaluated as a separate pass for electional spellcasting. For ordinary transit calculations, transit-to-transit is opt-in and adds a credit when enabled.
How does annual context (profection + solar return) factor in?
Annual context is capped, receipted background reported beside the timing score. It does not change minute-level totals or ranking, never relocates the natal chart, never creates election windows on its own, and never overrides a gate. The lord-of-year placement, profected house, and solar-return chart structure all contribute to that context.
Learning depth