The circle of signs that follows the apparent path of the Sun (ecliptic). also called the movable zodiac because it shifts slightly each year relative to the constellations of the sidereal zodiac. See also Precession of the Equinoxes.

The measuring system in which planetary longitudes are measured against the point in the sky where the Sun is on the first day of Spring. This is the system most used in Western Astrology. This is the system which uses the dates for each of the Astrological Signs that are listed in The signs of the Zodiac chapter.

Zodiacal system based on the movements of the seasons, as opposed to the Sidereal Zodiac, which is based upon actual stellar positions.

The tropical zodiac begins at 0 degrees Aries, where the Sun is located during the Spring Equinox. This system is used by most Western astrologers and throughout this book.

This system is most commonly used in Western astrology. It is the moving zodiac where the equinoxes and solstice points stay at the same zodiacal degree from year to year, keeping in step with the seasons.