Why your zodiac sign is different in Vedic astrology

If you were born on 8 August, Western astrology makes you a Leo. A Vedic kundli puts your Sun in Karka, which is Cancer. Your Moon sign and your rising sign have probably moved back one sign as well. Both systems use the same twelve signs with the same names; they start counting from different places.

I made Astro, a free birth chart calculator that casts both charts from the same birth details, so I used it to measure how often this happens. Across 20,000 random birth times between 1960 and 2010, the Vedic Sun sign was different from the Western one 79% of the time. The Moon sign and the rising sign were different just as often.

Two zodiacs, 24° apart

The Western zodiac follows the seasons. Aries starts at the March equinox, so the Sun enters Aries around 20 or 21 March every year.

The Vedic zodiac is fixed to the stars. The two zodiacs lined up about 1,700 years ago. Since then the Earth's axis has wobbled slowly, like a spinning top, and the equinox has drifted backwards against the stars by about 1° every 72 years. The gap between the two zodiacs is called the ayanamsa. By the Lahiri ayanamsa, which India's government uses, it is 24°13′ in 2026.

A Vedic chart subtracts that gap from every planet and from the ascendant. A sign is 30° wide, so anything in the first 24° or so of a Western sign falls into the sign before it. Only the last 6° of each sign stay put, which is where the four in five comes from.

Vedic Sun sign dates

The Sun moves about 1° a day, so the 24° gap comes to about 24 days. In a Vedic chart the Sun enters each sign around the 13th to 17th of the month, where the Western dates fall between the 19th and the 23rd.

Two of these dates are festivals. Makar Sankranti, on 14 or 15 January, is the day the Sun enters Makara (Capricorn). Baisakhi and Vishu fall around 14 April because that's when it enters Mesha (Aries).

These are the dates for births between 1960 and 2010 by the Lahiri ayanamsa, give or take a day. If you were born on a day the Sun changed sign, your birth time decides which one you get.

Sign	Western dates	Vedic dates
Aries (Mesha)	21 March to 19 April	14 April to 13 May
Taurus (Vrishabha)	20 April to 20 May	14 May to 14 June
Gemini (Mithuna)	21 May to 20 June	15 June to 15 July
Cancer (Karka)	21 June to 22 July	16 July to 15 August
Leo (Simha)	23 July to 22 August	16 August to 15 September
Virgo (Kanya)	23 August to 22 September	16 September to 16 October
Libra (Tula)	23 September to 22 October	17 October to 15 November
Scorpio (Vrishchika)	23 October to 21 November	16 November to 15 December
Sagittarius (Dhanu)	22 November to 21 December	16 December to 13 January
Capricorn (Makara)	22 December to 19 January	14 January to 12 February
Aquarius (Kumbha)	20 January to 18 February	13 February to 13 March
Pisces (Meena)	19 February to 20 March	14 March to 13 April

In India, your sign means your Moon sign

When someone in India asks for your rashi, they mean the sign the Moon was in when you were born. Kundli matching and rashifal columns go by it, while Western horoscopes go by the Sun sign.

The Moon changes sign every two and a half days, so you need your birth time as well as the date to know it. The same 24° gap moves it back a sign about four times in five. And since the Moon can be in any sign when the Sun is in yours, only about one person in twelve has a rashi that matches their Western Sun sign.

The same birth in both systems

Someone born in Delhi at 8 in the morning on 8 August 1996 gets these signs:

	Western	Vedic
Sun	Leo	Karka (Cancer)
Moon	Gemini	Vrishabha (Taurus)
Rising sign	Virgo	Simha (Leo)

All three moved back one sign, so someone who grew up reading Leo horoscopes has Vrishabha as their rashi. The Vedic chart also gives the Moon's nakshatra, which here is Rohini, the fourth of the 27.

Which one is right?

Each system is consistent with itself. Western astrology ties the signs to the seasons, so Aries always begins at the March equinox. Vedic astrology ties them to the stars, which is why its dates move a day later every 72 years or so. For Western horoscopes, use your Western signs. For a kundli, kundli matching or your rashifal, use the Vedic ones.

Find your own signs

Enter your date, time and place of birth on Astro. The Vedic tab shows your rashi, nakshatra and lagna, with the Rashi, Navamsa and Dashamsa charts. The Western tab shows the chart wheel with your Sun, Moon and rising signs. Without a birth time, it casts the chart for noon and leaves out the rising sign, which changes about every two hours.

Lahiri is the default ayanamsa, and Settings has a dozen others, including KP and Raman. If another app gave you a different chart, this post explains why kundli apps disagree.

Astro is free and does all its calculations in your browser, so your birth details aren't sent anywhere.