Astrology
Astrology is the practice of reading meaning into where the planets stood at a given moment. This section covers the whole of it as we treat it: positions calculated from the date rather than looked up in a table, sign dates given to the minute for a specific year, and every traditional claim labeled as tradition.
18 pages · printable
The 2027 Sky Calendar — free PDF
Every retrograde, eclipse, new and full moon of 2027 to the minute, already converted to your city. A month to a page, ready to print.
How long does each planet stay in one sign?
From about two days to more than a quarter of a century. The Moon needs about 2.3 days per sign and Jupiter about a year. Pluto’s longest stay since 1900 began in Cancer in 1912 and lasted 26.8 years; its shortest began in Scorpio in 1983 and lasted 12 years. Uranus, Neptune and Pluto each spend roughly seven years or more in a sign, so everyone born in that window shares them, which is why a chart reads them as a generation rather than a person.
A stay runs from the first entry into a sign to the final entry into the next, so a retrograde loop back over the border counts toward it — which is why Mars can spend 7.7 months in one sign. The scale is logarithmic, so a day and a decade fit on one line.
What we do differently here
The signs are not equal in length
The Earth moves faster near perihelion, so the Sun crosses some signs quicker than others. Our dates are solved for each 30-degree boundary in the year you ask about, which is why they differ from the fixed calendar everyone prints.
Half the planets describe a generation, not a person
Between 1900 and 2050, Pluto stays in one sign for 12 to 27 years, Neptune for 14 to 15 and Uranus for 7 to 9. A reading that treats those as personal traits is describing everyone born in the same window. The Moon changes sign about every 2.3 days — that one is genuinely yours.
The ascendant needs the time, and it is unforgiving
It moves about 15 degrees an hour on average, so half an hour of error shifts it noticeably and two hours move it a whole house. Where a birth time is uncertain we say which parts of the chart survive that and which do not.
What we calculate, and how precisely
In a birth chart born 1900 to 2030, the Sun, the Moon and every planet come from NASA JPL’s DE440 ephemeris, accurate to about an arcsecond and checked against Swiss Ephemeris; outside those years, from JPL orbital elements corrected for precession, about 0.2°. Dates and times of events (stations, sign changes, phases) come from NASA JPL’s DE440 ephemeris.
Checked against the sky, not against other websites
Every event time from 1900 to 2050 is recomputed with Swiss Ephemeris, eclipses are matched against NASA’s list for 2024–2030, and the ascendant is tested against sunrise, when it must equal the Sun. These checks caught real errors on this site in 2026 — a Moon sign up to a day out and an ascendant that was the descendant — and the pages now say so.
Sun-sign forecasts use solar houses
Daily, weekly and yearly horoscopes count your Sun sign as the first house. It is the traditional shortcut for a forecast without a birth time, and it is a shortcut: a chart cast for your actual time puts the same events in other houses.
Cite this page
AstroHot. “Astrology Explained: Charts, Signs, Houses and the Moon.” Accessed October 28, 2026. https://astrohot.com/astrology/
For Wikipedia
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