How we create our readings
Every number on this site comes from a calculation you can repeat. Every text is drafted with AI and edited by a person before it goes live.
Planet positions
We calculate positions with astronomy-engine, an open-source astronomy library. The calculator gives the geocentric position of each planet on the ecliptic of date, in the tropical zodiac used in Western astrology. Before launch we compared it with published ephemerides on eight known events, such as planets entering a sign and Venus and Mercury turning retrograde; the difference was under one arcminute in every case.
The North Node and Black Moon Lilith are mean positions. The node uses the standard formula from Jean Meeus, Astronomical Algorithms. For Lilith we take his mean apogee. Then we project it from the Moon's tilted orbit onto the ecliptic. That brings it within 0.02° of the mean Lilith that astro-seek.com prints. The true node can differ from the mean node by up to about a degree and a half. So its sign-change dates can differ by a few weeks from sites that use the true node. Check which one a site uses; the North Node calculator gives both. We do not calculate Chiron or the asteroids.
When the birth time matters
Without a birth time, we check the whole calendar day in US time zones, from midnight Eastern time to midnight Hawaii time. If a planet changed sign in that window, we show both signs and ask for the time. This happens most often with the Moon, which changes sign every two to three days.
Rising sign and midheaven
The rising sign calculator needs the birth time and place. It converts local time to Universal Time with the IANA time zone database built into your browser, which includes past time zone and daylight saving changes for each city. Sidereal time comes from astronomy-engine; the ascendant and midheaven follow from the standard spherical astronomy formulas. We compared the results with five published charts from Astro-Databank with birth-record times; the difference was under 0.02° in each. Without a birth time, the calculator does not guess a rising sign; it lists every sign that rose that day instead.
Birth places come from GeoNames (cities15000 list, licensed under CC BY 4.0): every US city with at least 15,000 people and cities elsewhere with at least 75,000.
Our statistics
Shares on each page come from running every date from January 1, 1930 to December 31, 2025 (35,064 days) through the same calculation, at noon UTC. A share is the percentage of those dates, not of people: birth rates differ by year and season, so the share of people can differ slightly. The full tables, with US births by sign kept separate and CSV downloads, are on our zodiac sign and retrograde statistics page, and every other count, with the sample it used, is listed on our research page.
Famous people
We take birth dates from Wikidata and use only people with a single sourced date of birth. Because birth times are often unknown, we list a person on a page only if the planet stayed in that sign for their whole birthday in every time zone.
How pages are written
Meanings follow the Western astrological tradition. A draft is written with AI from our notes and data, then a person edits it, checks every fact and number against the calculation, and removes anything that sounds like a prediction or a promise. Pages are signed by the editorial team.
Each article shows the date of its last real revision under the title, meaning a change to the text or the data. Rebuilding the site leaves that date alone. Pages that rely on outside material, such as a library, an eclipse table or an old textbook, end with a Sources list that links to it.
What we do not claim
Astrology is a symbolic tradition. We describe what a placement means within it; we do not claim it predicts events, and we do not give medical, legal or financial advice. Read a result as a set of questions about yourself.
Last updated October 17, 2026