What a zodiac sign is
The Sun’s visible yearly path across the sky — the ecliptic — is divided into twelve equal parts of 30°. The count starts from the spring equinox point: the Sun passes it on March 20 or 21, and Aries begins at this degree. This zodiac is called tropical — it’s tied to the seasons, not to the stars. Western astrology and our natal chart calculation use it.
The signs are named after constellations but don’t coincide with them. The equinox point slowly shifts against the stars — this is precession, a full circle in roughly 26 thousand years — and the constellations have moved away from the signs of the same name by almost a whole sign. Jyotish counts the signs from the stars: by our calculation with the Lahiri ayanamsa the difference on January 1, 2026 is 24.2°, and the Sun sign in Jyotish is the previous one for most people. There is no thirteenth sign either: from late November to mid-December the Sun passes through the constellation Ophiuchus, but signs aren’t constellations, and there are always twelve of them.
Sign dates: why tables disagree
Horoscope tables give the same dates for all years, while the Sun enters a sign at a different hour every year, and the boundary wanders by a day or two. By our calculation for 1950–2030, Moscow time, the Sun entered Aries on March 20 in 49 years out of 81 and on March 21 in 32. So on border days the Sun sign depends on the year and hour of birth, and on the other days it doesn’t. East of Moscow the boundary can fall a day later.
“For sure” means the days when the Sun is in the sign in any year from 1950 to 2030. The signs take different amounts of time to pass: the Earth’s orbit is an ellipse, and in early January the Earth is closer to the Sun and moves faster. The Sun passes through Capricorn in 29.4 days, Cancer — in 31.5.
Elements and modalities
Each sign is a combination of one of the four elements and one of the three modalities: four times three makes twelve, with no repeats.
In each row, in order: the cardinal, fixed and mutable sign.
- Fire — acting in a rush: starting without waiting for permission.
- Earth — bringing things to a tangible result: money, an object, order.
- Air — acting through people and words: negotiating and keeping connections.
- Water — acting by instinct: catching people’s mood and the moment.
The modality describes what a sign does with what has been started: cardinal starts and leads, fixed holds and sees through, mutable adapts and changes. The cardinal signs open the seasons in the Northern Hemisphere: Aries — spring, Cancer — summer, Libra — autumn, Capricorn — winter.
One sign — four roles
“I’m an Aries” speaks only of the Sun. A sign has four roles in a chart, and they’re different.
- The Sun in a sign — how a person goes about things and what they strive for. Known from the date, except on border days.
- The Moon in a sign — what restores your strength and how the first reaction comes. The Moon passes through a sign in 2–2.5 days and on 43.9% of dates changes sign within the day (our measurement, 1950–2025) — then you need the hour of birth.
- The Ascendant in a sign — manner and first impression. You need an exact time and city: in Moscow Aries rises for 42 minutes a day, while Leo, Virgo, Libra and Scorpio take three hours each.
- The sign at the start of a house — the style in which the affairs of that area go. It also needs an exact time; more in the section on houses.
That’s why the description of “your sign” doesn’t fit everyone: a person with the Sun in Aries most often has the Moon and the Ascendant in other signs. There’s a simpler explanation too: descriptions of signs have no evidence base. That’s why every description on the sign pages has a sign that it’s not about you.
Rulers of the signs and classical dignities
Each sign has a ruler — the planet that is its master. In the classical scheme there are seven planets for twelve signs: the Sun and the Moon got one each, the rest two each. After the discovery of Uranus, Neptune and Pluto, modern astrology gave them Aquarius, Pisces and Scorpio, while the classical one kept the former masters. The dispute isn’t settled, and the site names both.
The classical scheme knows three more concepts. Exaltation — the sign where a planet is in a particularly strong position; detriment — the sign opposite its own; fall — the sign opposite its exaltation. Modern schools rarely use them, and the site’s calculation doesn’t take them into account, but they appear in books — that’s why they’re named here.
On the right: exaltation / detriment / fall; a dash means the sign has no such planet. Only the seven classical planets: Uranus, Neptune and Pluto have no dignities in the tradition.
What here is astronomy, and what is interpretation
The boundaries of the signs and the positions of the planets are astronomy: they can be recalculated from any ephemeris and you’ll get the same degrees. The dates on these pages are our calculation from the NASA JPL DE440 ephemeris, and you can verify it. But that Aries is about beginnings and Pisces about compassion is interpretation built up over two thousand years. It has no evidence base, so the descriptions of signs here are a description of the system, and each one says when it’s not about you.