The Zodiac · a working tool
Zodiac Signs and Dates.
Enter a birthdate to find its western zodiac sign, then read the full table of tropical date ranges. The scheme is old: Babylon divided the ecliptic into twelve equal parts, and Ptolemy fixed the arrangement we still use. What follows is that lineage, not a horoscope.
The 12 zodiac signs and their dates
Standard tropical date ranges. Boundary days are honest approximations: the Sun’s exact crossing can fall a day either side depending on the year and time zone.
| Sign | Dates | Symbol | Element | Ruler |
|---|---|---|---|---|
| Aries | March 21 to April 19 | Ram | Fire | Mars |
| Taurus | April 20 to May 20 | Bull | Earth | Venus |
| Gemini | May 21 to June 20 | Twins | Air | Mercury |
| Cancer | June 21 to July 22 | Crab | Water | the Moon |
| Leo | July 23 to August 22 | Lion | Fire | the Sun |
| Virgo | August 23 to September 22 | Maiden | Earth | Mercury |
| Libra | September 23 to October 22 | Scales | Air | Venus |
| Scorpio | October 23 to November 21 | Scorpion | Water | Mars (Pluto in modern practice) |
| Sagittarius | November 22 to December 21 | Archer | Fire | Jupiter |
| Capricorn | December 22 to January 19 | Sea-goat | Earth | Saturn |
| Aquarius | January 20 to February 18 | Water-bearer | Air | Saturn (Uranus in modern practice) |
| Pisces | February 19 to March 20 | Fishes | Water | Jupiter (Neptune in modern practice) |
Born on a cusp? Read this first
The word cusp simply names the point where one sign ends and the next begins. In astronomy the Sun crosses that point at a single, precise instant, so a birth falls on one side or the other, never genuinely between two signs at once. The popular idea that cusp babies are a blend of both neighbours is a twentieth-century newspaper convention: when syndicated horoscope columns needed to route every reader to a single paragraph, they softened the borders rather than publish exact ephemeris times.
What is real is the drift. Because the tropical year is about 365.25 days and the ecliptic is split into twelve equal signs, the Sun reaches each boundary at a slightly different clock time every year. A crossing listed here as, say, October 23 can occur late on October 22 or early on October 24 in a given year and time zone. If your birthday sits on a boundary date in the table, the only way to settle the sign with certainty is to check the Sun’s position for your exact date, time, and place of birth.
Where the signs come from
Each sign carries a longer memory than any monthly forecast. A brief note on the imagery behind all twelve; the full monographs live in The Zodiac department.
- Aries · the Ram
- This stretch of sky was the Babylonian "Hired Man" (MUL.LU.HUN.GA) before Greek astronomers recast it as the ram of the Golden Fleece.
- Taurus · the Bull
- Among the oldest recorded constellations. The Babylonian "Bull of Heaven" (GU4.AN.NA) is the beast slain in the Epic of Gilgamesh.
- Gemini · the Twins
- The Babylonian "Great Twins," later read by the Greeks as Castor and Pollux, the sons of Leda.
- Cancer · the Crab
- A faint cluster Ptolemy still logged in the Almagest; Greek myth tied it to the crab crushed underfoot by Heracles.
- Leo · the Lion
- A lion has held this seat since the Babylonian star lists. Its brightest star, Regulus, was one of Persia’s four "royal stars."
- Virgo · the Maiden
- Linked across cultures to grain goddesses, from Babylonian Shala to Greek Demeter and Persephone, mirroring the harvest season.
- Libra · the Scales
- The only inanimate sign. These stars were once the claws of the Scorpion until Roman astronomers set them apart as the Scales.
- Scorpio · the Scorpion
- A Babylonian original (GIR.TAB). In Greek myth the scorpion stings the hunter Orion, who still flees it across the night sky.
- Sagittarius · the Archer
- Descends from Pabilsag, the Babylonian centaur-archer, one of the figures carved on kudurru boundary stones.
- Capricorn · the Sea-goat
- The sea-goat appears on Babylonian boundary stones a thousand years before Ptolemy catalogued the constellation in the Tetrabiblos.
- Aquarius · the Water-bearer
- Tied to the Babylonian water-god Ea and the rainy season; the Greeks later named the figure Ganymede, cupbearer to the gods.
- Pisces · the Fishes
- Two fish joined by a cord, a Babylonian image echoed in the Greek tale of Aphrodite and Eros escaping the monster Typhon.
The through-line runs from Mesopotamian star lists such as the MUL.APIN compendium to Ptolemy’s catalogues: a cultural inheritance worth reading as history, whatever you make of the astrology.
Read every sign in full
The Twelve, our sign monographs, take each sign as literature: its myth, its sources, and its pictures. Open any one from the department’s The Zodiac.
Common questions
What are the zodiac sign dates?
The twelve western (tropical) signs run in order from Aries (March 21) through Pisces (ending March 20). Each sign spans roughly 30 degrees of the ecliptic, or about a month.
What does it mean to be born on the cusp?
A "cusp" birthday falls on or near the day the Sun crosses from one sign into the next. There is a single exact moment of that crossing, so you are still born under one sign, not two, even if popular horoscope columns once blended the neighbours.
Why do the boundary dates change from year to year?
The tropical year is about 365.25 days but is split into twelve signs, so the Sun reaches each boundary at a slightly different clock time each year. A crossing can therefore land a day earlier or later depending on the year and your time zone.
Go deeper on one sign: read Scorpio dates, traits, and mythology or Capricorn dates, traits, and mythology, culturally literate looks at where the images come from. The Twelve monographs cover every sign in The Zodiac department.
Know two signs already? See how the tradition reads the pair with our zodiac compatibility checker, which shows its working by element, modality, and aspect.
Keep reading: browse the full essay archive or learn more about ZOD Culture.