Gemini (♊︎) ( JEM-in-eye Greek: Δίδυμοι, romanized: Dídymoi, Latin for "twins") is the third astrological sign in the zodiac. Under the tropical zodiac, the sun transits this sign between about May 21 to June 21. Gemini is represented by the twins, Castor and Pollux, known as the Dioscuri in Greek mythology. It is known as a positive, mutable sign.