Zodiac Sign Finder

A sun sign lookup answers one question: which 30-degree slice of the ecliptic held the Sun on a given date. Western astrology uses the tropical zodiac, whose zero point is the March equinox rather than any star, so the twelve signs are equal divisions of the Sun's annual path and do not line up with the constellations that share their names. The date ranges shown here are therefore approximate. The tropical year is 365.2422 days while the civil calendar runs on whole days with leap corrections, so the Sun's entry into each sign drifts by up to about a day across the leap cycle - the Aries ingress falls on 19, 20 or 21 March depending on the year. This is also why birthdays within about two days of a boundary are flagged as cusp dates. The supporting attributes follow a fixed combinatorial scheme. Four elements crossed with three modalities give exactly twelve unique pairings, one per sign, so no two signs share both. Rulerships are older still: the traditional set assigns the seven visible bodies, and the modern additions came with discovery - Uranus to Aquarius after 1781, Neptune to Pisces after 1846, Pluto to Scorpio after 1930. The main caveat is astronomical. The IAU constellation boundaries fixed by Eugene Delporte in 1930 are of very unequal size, and the Sun spends roughly eighteen days each year in Ophiuchus, which no zodiac sign covers. Sun-sign traits and compatibility rules have no measured predictive value.

The equal twelve-sign zodiac was standardized by Babylonian astronomers by about the fifth century BCE, replacing the uneven constellation scheme of the older MUL.APIN compendium of roughly 1000 BCE with twelve tidy divisions of 30 degrees each. Greek astronomers inherited it. Hipparchus discovered the precession of the equinoxes around 130 BCE, and Claudius Ptolemy fixed the tropical convention in the Tetrabiblos about 150 CE by placing 0 degrees Aries at the vernal point, along with the element and modality classifications that still structure sign descriptions. The split between signs and constellations widened steadily from that point, since precession moves the equinox about one degree every 72 years. By the twentieth century the offset had reached roughly 24 degrees, which is why Indian sidereal astrology assigns many people a different sign from Western astrology. Mass-market sun-sign reading is a recent development. Alan Leo, who died in 1917, stripped chart interpretation down to something a general readership could follow, and the newspaper horoscope column dates precisely to August 1930, when R. H. Naylor wrote a piece for the Sunday Express on the newborn Princess Margaret and was given a regular slot after it drew heavy reader response. That format, keyed to birth date alone, is what made the twelve sun signs household knowledge.