Gemini: Dates, Meaning, and the Twins Explained

The twins zodiac sign — its dates, symbol, mythology, and the two bright stars that mark their heads.

Gemini is the third sign of the zodiac, covering May 21 through June 20. Its symbol is a pair of twins, marked in the sky by two close, bright stars — Castor and Pollux — sitting side by side at the top of the constellation like a pair of matched heads.

Gemini dates and basic facts

Where the twins symbol comes from

The constellation is named for Castor and Pollux, the Dioscuri — twin brothers of Helen of Troy in Greek myth, but only half-brothers by blood: Castor was the mortal son of Tyndareus, king of Sparta, while Pollux was the immortal son of Zeus. When Castor died, Pollux was so grief-stricken he begged Zeus to let him share his own immortality with his brother rather than live on alone. Zeus granted it, and the two were placed together in the sky — bound in death the same way they'd been inseparable in life.

What Gemini is said to represent

As a mutable air sign ruled by Mercury — the planet of communication and quick thinking — Gemini is traditionally associated with curiosity, wit, and adaptability, along with a duality that maps directly onto its twin symbolism: two sides of the same personality, capable of holding contradictory ideas or moods at once. The mutable modality reinforces this — Gemini is built for change, conversation, and constant movement between ideas rather than settling on one.

How easy Gemini is to find in the night sky

Castor and Pollux make Gemini one of the more approachable zodiac constellations — both stars are bright enough to see even under moderate light pollution, and their close pairing at the "head" of the twins makes the overall shape easier to orient than fainter, more scattered zodiac figures like Cancer or Pisces.

See your own sign's star map

CosmicByMe renders every zodiac constellation — including easy-to-spot ones like Gemini — from real star and constellation-line data, centered on the sky as it actually looked from your birth date, time, and location. Generate your own card on the homepage to see it.