What dates is Gemini?

From about May 21 to June 20. Whether a May 20 or a June 20 birthday counts as Gemini comes down to the hour of birth in some years, and a calculated chart answers it.

Is Gemini an air sign?

Yes, with Libra and Aquarius. The air signs deal in ideas, exchange and connection, and Gemini, the mutable one, does so fastest and least predictably.

Why is Gemini the twins?

The constellation has two bright stars side by side, Castor and Pollux, named for twin brothers in Greek myth. In the sign, the pair stands for doubleness: two views, two conversations, two things at once. The sign and the constellation no longer share the same stretch of sky.

Astrology basics · The twelve signs

What Gemini means: the sign that asks the next question

Gemini is the third sign, the sixty-to-ninety-degree arc of the ecliptic. Air, mutable, ruled by Mercury, opposite Sagittarius. The Sun crosses Gemini from about May 21 to June 20, the last month of northern spring, and the sign answers the 3rd house: siblings, neighbors, errands, the daily back-and-forth of talk.

Element: Air
Modality: Mutable
Ruling planet: Mercury
Sun in Gemini: About May 21 to June 20
Opposite sign: Sagittarius
Natural house: The 3rd

The third twelfth of the ecliptic

Like the other eleven, Gemini is measured from the March equinox, not from the stars that share its name (the Aries page has the reason). It is the third sign and the first air sign, and it is mutable: the mutable signs end each season, when one kind of weather is turning into the next, and the sign carries that quality of being between two things. The Sun's dates in Gemini vary by a day from year to year.

A planet in Gemini talks

Gemini gives a planet two of everything and a question about each. Whatever the planet governs is done quickly, in words, and in more than one direction at once. Venus in Gemini is drawn by a conversation and stays for the next one. Mars in Gemini argues the point, and argues the other side ten minutes later for the exercise. Saturn in Gemini works at getting the sentence exactly right, and keeps back the one that matters.

Gemini Sun, Gemini Moon, Gemini rising

A Gemini Sun comes alive mid-conversation, with three tabs open and a friend on the phone. It reads the first chapter of four books in a week and gives a fair account of all four at dinner.

For a Gemini Moon the feeling is not real until it has been said to someone, and once said it is dealt with. The safe house has a person to text at eleven at night and a radio on in the kitchen, and the silent one is left for the cafe.

Gemini rising meets a stranger with a question and has asked four more before the first is answered. The impression is quick and light, and halfway through the second answer it has spotted someone across the room it has to say hello to.

Sagittarius opposite, Mercury, the 3rd house

Sagittarius is the opposite sign: errands and neighbors at one end, journeys and belief at the other; a Gemini planet has to deal with whatever is placed across from it. Mercury rules Gemini, and the planet's domain, taking things in and saying them, is the sign's whole business. The matching house is the 3rd.

See Gemini in your own chartA free birth chart, with the reading, from your date, time and place.

Questions

What dates is Gemini?: From about May 21 to June 20. Whether a May 20 or a June 20 birthday counts as Gemini comes down to the hour of birth in some years, and a calculated chart answers it.
Is Gemini an air sign?: Yes, with Libra and Aquarius. The air signs deal in ideas, exchange and connection, and Gemini, the mutable one, does so fastest and least predictably.
Why is Gemini the twins?: The constellation has two bright stars side by side, Castor and Pollux, named for twin brothers in Greek myth. In the sign, the pair stands for doubleness: two views, two conversations, two things at once. The sign and the constellation no longer share the same stretch of sky.