Astronomical calculations
We use Astronomy Engine 2.1.19 under the MIT license. Zodiac placements use apparent geocentric ecliptic longitude in the Western tropical zodiac. This is not the same as naming the astronomical constellation behind an object. The Moon is geocentric; we do not apply a birth-location parallax correction.
Birth charts support 1900 through today. The ascendant is the eastern intersection of the horizon and ecliptic, without atmospheric refraction. We support it within 66 degrees north or south; outside this validated range we omit ascendant and houses. Houses use the whole-sign system only.
Major aspects use fixed maximum orbs: conjunction and opposition 8°, trine and square 6°, sextile 4°. These are chosen interpretive conventions, not physical boundaries. Positions are approximate and should not be used for navigation or safety-critical observation.
Birth times and places
City coordinates and IANA timezone identifiers come from GeoNames, licensed CC BY 4.0. Confirm the selected city. Historical offsets are resolved for the entered birth date using the deployed timezone database, not today’s offset. Timezone history before 1970 may be incomplete; a recorded local time can also be imprecise.
A repeated clock time during a timezone change requires you to choose which occurrence you mean. A nonexistent time is rejected. Unknown birth times span the complete local birth date; results show ranges and possible signs, with no rising sign or houses. A placement near a boundary deserves caution.
Moon tools
The lunar phase and illuminated fraction describe related but distinct geometry. New/full moon events are searched using the ephemeris, not a fixed 29-day counter. Event times are stored as UTC instants and displayed in your chosen timezone. Date-only snapshots use noon in that zone.
The Moon’s astrological sign is a separate tropical longitude classification. Northern and southern hemisphere artwork changes the illustration, not the computed phase. A two-date Moon keepsake does not test whether people are soulmates.
Numerology and creative tools
Numerology uses our documented modern Pythagorean convention. Birth-date digits are summed and reduced, retaining core master numbers 11, 22 and 33 when encountered. Name letters use repeating 1–9 values. A, E, I, O and U are vowels; Y is a consonant. Personal years and months reduce to 1–9. Other schools use different rules.
Tarot cards are drawn using cryptographic randomness without replacement. Interpretations are authored reflection prompts. Aura and element quizzes use published scoring; Oracle Doors follows the choices you make. None measures a physical aura or reveals a factual future.
Sources and verification
Calculation tests compare selected results to independent JPL Horizons and US Naval Observatory references, using matching coordinate conventions and documented tolerances. The code and operational documentation preserve reference dates and method versions. GeoNames may omit small settlements; choosing a nearby city can introduce positional uncertainty.