Tropical zodiac — Astrology glossary

The tropical zodiac anchors the signs to the seasons rather than the constellations, beginning Aries at the spring equinox in the Northern Hemisphere. Each sign then occupies a fixed thirty-degree slice measured from that point. It is the standard framework of Western astrology and is what most horoscopes and birth-chart calculators use by default. Because the equinox slowly shifts against the background stars through precession, the tropical signs no longer line up with the constellations of the same name; tropical Aries now sits largely in front of the stars of Pisces. This matters because it explains why a tropical Sun sign can differ from the constellation the Sun was actually in at birth, a discrepancy critics often raise and that distinguishes tropical from sidereal practice. For example, a 1 May birth gives a tropical Taurus Sun.