About Ekliptio and our method

Ekliptio is published by Daniel Gavalec. It is a set of free astrology and calendar calculators that start from the real sky: every result is computed from astronomical positions for your exact birth moment, and every page says how.

How we calculate

• Planet positions come from Astronomy Engine (MIT license): apparent geocentric positions on the true ecliptic of date, with IAU 2006 precession and IAU 2000B nutation, light-time and aberration.
• Your local birth time is converted to Universal Time with the historical rules of the IANA time zone database. When a time was skipped or repeated by a clock change, the calculator tells you and lets you choose. For births before about 1950 you can use local mean time or a custom UTC offset.
• Houses: Placidus (default), Koch, Equal and Whole sign. Near the poles, where Placidus and Koch are undefined, we switch to Porphyry and say so.
• Chiron comes from a NASA/JPL Horizons table (1800–2149); the Chinese New Year is computed astronomically and matches the Hong Kong Observatory tables for 1901–2100.
• Everything runs in your browser. Your birth data is never sent to a server.

How we test

Automated tests compare our results with NASA/JPL Horizons (DE441) for 16 published birth records from 1856 to 1975: the Sun and planets agree within about 1 arcminute, the Moon within 2, and the Ascendant and Midheaven within 3. These are maxima on that sample, not a guarantee for every date; outside it the documented accuracy of Astronomy Engine applies.

Interpretations

Astronomical positions are measurements. Astrological and numerological meanings are traditional symbolism, written in our own words as tendencies – for entertainment and self-reflection, not predictions or advice.

Data and credits

• Place data © GeoNames, CC BY 4.0.
• Star positions and constellation lines in the sky map: d3-celestial by Olaf Frohn (BSD-3-Clause), from the Hipparcos and Yale Bright Star catalogues.
• Reference ephemerides for testing: NASA/JPL Horizons.

Advertising

The site is funded by ads. Ads never influence results and are always labelled.