Astrology
A guide to astrology and related traditions
Astrology: A Guide to the Zodiac and Its Traditions
Astrology is a family of cultural and symbolic traditions that interpret relationships between celestial cycles and human life. Explore the Western zodiac, Indian Jyotisha, the Chinese zodiac and numerology—and find ICIA’s guides to constellations and crystals.
Western Astrology and the 12 Zodiac Signs
In Western astrology, the tropical zodiac divides the ecliptic into twelve equal signs. A birth chart maps the positions of the Sun, Moon and planets for a particular date, time and place. The signs below are a starting point; a Sun sign alone is not a complete birth-chart reading.
- AriesMar 21 – Apr 19
- TaurusApr 20 – May 20
- GeminiMay 21 – Jun 20
- CancerJun 21 – Jul 22
- LeoJul 23 – Aug 22
- VirgoAug 23 – Sep 22
- LibraSep 23 – Oct 22
- ScorpioOct 23 – Nov 21
- SagittariusNov 22 – Dec 21
- CapricornDec 22 – Jan 19
- AquariusJan 20 – Feb 18
- PiscesFeb 19 – Mar 20
Sign dates are approximate and can vary slightly by year and time zone. If a birth date falls near a sign boundary, a chart calculated with the birth year, time and location is needed to determine the placement.
Different Systems, Different Frameworks
These traditions have distinct histories and methods. They should not be treated as interchangeable versions of one zodiac.
Western Astrology
Western astrology commonly uses the tropical zodiac, aligned to the seasonal equinoxes. Its practice includes natal charts, transits and other interpretive techniques. The twelve zodiac signs are symbolic divisions; they are not the same thing as the visible constellations, whose sizes and positions differ.
Indian Jyotisha
Jyotisha is a diverse astrological tradition from India. Many Jyotisha chart calculations use a sidereal zodiac and an ayanāṃśa to relate zodiac positions to the fixed-star framework. Methods and interpretations vary across schools; Jyotisha is not simply another name for Western astrology.
Chinese Zodiac
The Chinese zodiac associates twelve animal signs with a repeating cycle of years. In broader Chinese calendrical traditions, the sexagenary cycle combines the ten Heavenly Stems and twelve Earthly Branches, including the five phases. The year boundary depends on the calendrical convention being used, so a birth year alone may not be enough near the boundary.
Numerology
Numerology interprets numbers—often derived from names or birth dates—within symbolic systems. It is not a branch of astronomy or astrology, even when discussed alongside them in popular spiritual content.
Horoscopes and Birth-Chart Interpretation
A horoscope may refer to a chart for a specific moment or to a short forecast written for a sign. A natal-chart interpretation considers the chosen astrological system and the chart’s placements and relationships. Interpretations are symbolic readings, not established scientific predictions.
For a useful reading, first identify the system being used and the information required by that method. Birth time and birthplace can affect chart angles and house placements. If the time is unknown, some chart details may be uncertain.
Constellations and Crystals
Crystal and zodiac associations vary across traditions, authors and contemporary practices. Treat them as cultural or personal symbolism: there is no established scientific evidence that a crystal changes personality, predicts events or treats a health condition.
- 12 Constellations and Crystals Explore the dedicated sign-and-crystal navigation guide.
- Constellation Article Archive Browse ICIA’s articles filed under Constellation.
- Aries Crystals Read the existing ICIA article about crystal associations for Aries.
- Sagittarius Crystals Read the existing ICIA article about crystal associations for Sagittarius.
Crystals are not medical treatments. Do not use astrology or crystal practices to diagnose a condition, replace professional care or delay seeking medical advice.
