If you have ever checked your sign on an Indian (Vedic) astrology app and a Western one, you may have got two different answers. You are not imagining it. The two traditions use different zodiacs: Western astrology uses the tropical zodiac, and Vedic astrology uses the sidereal zodiac.

Neither is wrong. They measure the sky from different starting points. Here is how each works and how to know which sign you are in each system.

The tropical zodiac: tied to the seasons

The tropical zodiac is the one used in most Western astrology, including horoscopes in magazines and on this site.

It starts at the spring equinox, around March 20, when day and night are about equal. That moment is 0° Aries. From there, the year is divided into twelve equal signs of 30 degrees each. So:

  • Aries begins at the spring equinox.
  • Cancer begins at the June solstice.
  • Libra begins at the September equinox.
  • Capricorn begins at the December solstice.

Because it follows the seasons, the tropical zodiac never drifts against the calendar. Aries season always starts in late March.

The sidereal zodiac: tied to the stars

"Sidereal" means "of the stars." The sidereal zodiac lines the signs up with the actual star constellations as they appear today.

Over thousands of years, Earth's slow wobble (called precession) has shifted the stars against the seasons. When the zodiac was first laid out, the two systems roughly matched. Today they are about 24 degrees apart, which is close to a whole sign.

Vedic astrology (Jyotish) uses the sidereal zodiac. Different schools use slightly different correction values, called ayanamsas. The most common in India is the Lahiri ayanamsa.

How far apart are they?

About 24 degrees in 2026, growing by roughly one degree every 72 years. In practice that means:

  • If you were born in the first three weeks or so of your Western sign, your sidereal Sun sign is probably the sign before.
  • If you were born in the last week or so of your Western sign, your sidereal Sun sign is probably the same.

For example, someone born on April 5 is an Aries in Western astrology but usually a Pisces in Vedic astrology. Someone born on April 17 is an Aries in both systems, because sidereal Aries starts around April 14. Someone born on May 10 is a Taurus in Western astrology and an Aries in Vedic.

Sidereal Sun sign dates

These are approximate dates for the Sun's sidereal signs today, using the Lahiri system. They shift by a day between years.

  • Aries: about Apr 14 to May 14.
  • Taurus: about May 15 to Jun 14.
  • Gemini: about Jun 15 to Jul 16.
  • Cancer: about Jul 17 to Aug 16.
  • Leo: about Aug 17 to Sep 16.
  • Virgo: about Sep 17 to Oct 17.
  • Libra: about Oct 18 to Nov 16.
  • Scorpio: about Nov 17 to Dec 15.
  • Sagittarius: about Dec 16 to Jan 14.
  • Capricorn: about Jan 15 to Feb 12.
  • Aquarius: about Feb 13 to Mar 14.
  • Pisces: about Mar 15 to Apr 13.

You may recognize some of these dates. Makar Sankranti, in mid-January, marks the Sun entering sidereal Capricorn. Many Indian new year festivals in mid-April mark the Sun entering sidereal Aries.

Moon sign matters more in Vedic astrology

There is another big difference between the two traditions. Western astrology puts the Sun sign front and center. Vedic astrology usually puts more weight on the Moon sign (called the rashi) and on the rising sign (lagna).

So if someone in India asks "what is your rashi?", they mean your sidereal Moon sign, not your Western Sun sign. Your Moon sign shifts back by the same 24 degrees in the sidereal zodiac. For more on what the Moon means in a chart, read our moon sign meaning guide.

Which zodiac should you use?

That depends on which tradition you want to learn from.

  • Use the tropical zodiac if you read Western horoscopes, follow psychological astrology, or want your signs to match the seasons.
  • Use the sidereal zodiac if you follow Vedic astrology, use nakshatras (the 27 lunar mansions), or come from a family tradition that does.

Many people find that both feel true in different ways. Your tropical chart might describe your personality and your sidereal chart your karma and life timing, as some astrologers put it.

Astrofio uses the tropical zodiac for horoscopes, sign pages and charts. If you want to see your full Western chart, a free birth chart shows every planet by sign and house. For the familiar Western sign dates, start with the Aries sign page and follow the wheel from there.

FAQ

Why is my zodiac sign different in Vedic astrology?

Vedic astrology uses the sidereal zodiac, which follows the stars. Western astrology uses the tropical zodiac, which follows the seasons. The two are about 24 degrees apart, so many people's Vedic Sun sign is one sign earlier.

Is the sidereal zodiac more accurate?

Each is accurate for what it measures. Sidereal matches the constellations. Tropical matches the seasons. Astrologers in each tradition have centuries of practice behind their choice.

Which zodiac does NASA use?

NASA does not use astrology. Astronomers do describe the Sun's position against the real constellations, which is closer to the sidereal idea but uses unequal constellation sizes.

What is my sidereal Sun sign?

If you were born in the first three weeks of your Western sign, your sidereal Sun sign is probably the sign before. In the last week or so, it is likely the same sign. The date list above gives the details.

What is a rashi?

Rashi is the Sanskrit word for a zodiac sign. In everyday Indian use, "your rashi" usually means your Moon sign in the sidereal zodiac.