How we write and check this guide

The date convention

Sign dates follow one conventional tropical table throughout the site: Aries March 21–April 19, Taurus April 20–May 20, Gemini May 21–June 20, Cancer June 21–July 22, Leo July 23–August 22, Virgo August 23–September 22, Libra September 23–October 22, Scorpio October 23–November 21, Sagittarius November 22–December 21, Capricorn December 22–January 19, Aquarius January 20–February 18 and Pisces February 19–March 20. February 29 belongs to Pisces.

Because the Sun’s entry into each sign moves by up to a day between years, we also publish the exact moments, calculated from NASA JPL’s DE440s ephemeris with the open-source Skyfield library, for every year from 1920 to 2050.

How the tools calculate

• Sign finder: the conventional table above; birthdays within two days of a sign change are flagged.
• Birth chart calculator: Sun and Moon positions from Jean Meeus’s Astronomical Algorithms, planets from NASA JPL’s published approximate Keplerian elements, ascendant and midheaven from local sidereal time. Historical time zones come from your browser’s IANA time-zone database; places from GeoNames. Results are tested against DE440s.
• Chinese zodiac: the Lunar New Year date of every year from 1900 to 2099, plus the solar-term (Lichun) convention used in Four Pillars.
• Mayan day sign: the 260-day tzolk’in with the GMT correlation constant 584283.
• Horoscope today: the Moon’s tropical sign, computed daily; interpretations are fixed, labeled texts for each solar house, not personal predictions.

Sources and interpretation

Traditional associations (elements, modalities, rulers, exaltations, melothesia, Golden Dawn tarot attributions) are long-standing conventions and are described as such. Personality descriptions are our own summaries of how astrologers describe each sign. Astronomical facts come from NASA, the IAU and peer-reviewed research. For other traditions we rely on museum, academic and encyclopaedic sources and say when a popular chart lacks historical support.

How content and code are produced

Automated assistance is used to draft or revise some explanations and interface code. The site separates calculated astronomical positions from traditional interpretations. Calculation fixtures, link and HTML checks, and browser interaction tests check the implementation; those checks do not establish that an astrological interpretation predicts real events.

The birth chart wheel visualises the same calculated longitudes as its text table. Its five major aspects use a fixed 6° orb, a disclosed display choice rather than a universal standard. Unknown-time charts use noon and omit aspects, the rising sign and houses.

What we will not do

• Invent statistics, compatibility percentages, ratings, reviews or testimonials.
• Present astrology as a scientific or medical method.
• Guess celebrities’ birth times or publish unverified birth data.
• Change a year in a heading to simulate freshness.

Corrections

If you find an error, write to contact@zodiacsigns.it.com. Each page shows the date its content last changed.