Two zodiacs, anchored to different things
The Western (tropical) zodiac is fixed to the spring equinox, so it follows the seasons.
The Vedic (sidereal) zodiac is fixed to the actual stars.
Because the Earth wobbles slowly on its axis, the two starting points drift apart by about one degree every 72 years — a gap called the ayanamsa, now a little over 24 degrees. Since each sign is 30 degrees wide, that moves most people back one sign.
Your sign in both systems
| Western sign | Vedic sign if you were born… | Same sign in both systems from |
|---|---|---|
| Aries | Pisces: 21 Mar – 13 Apr | 14 Apr |
| Taurus | Aries: 20 Apr – 14 May | 15 May |
| Gemini | Taurus: 21 May – 14 Jun | 15 Jun |
| Cancer | Gemini: 21 Jun – 15 Jul | 16 Jul |
| Leo | Cancer: 23 Jul – 16 Aug | 17 Aug |
| Virgo | Leo: 23 Aug – 16 Sep | 17 Sep |
| Libra | Virgo: 23 Sep – 16 Oct | 17 Oct |
| Scorpio | Libra: 23 Oct – 15 Nov | 16 Nov |
| Sagittarius | Scorpio: 22 Nov – 15 Dec | 16 Dec |
| Capricorn | Sagittarius: 22 Dec – 13 Jan | 14 Jan |
| Aquarius | Capricorn: 20 Jan – 12 Feb | 13 Feb |
| Pisces | Aquarius: 19 Feb – 14 Mar | 15 Mar |
These dates shift by a day or so each year, and they only describe the Sun. Your Moon and rising signs move between systems too — a real chart works it all out exactly.
Questions
- Which sun sign is the real one?
- Neither is more real. They measure different things and each has been consistent for centuries; the useful question is which tradition you want to read yourself through.
- What is the ayanamsa?
- The measured gap between the tropical and sidereal zodiacs, a little over 24 degrees today and growing about one degree every 72 years. This site uses the Lahiri ayanamsa, the Indian government standard.
- Does my Moon sign change too?
- Yes. Every placement shifts, which is why a date range is only a rough guide.
- Do I need my birth time?
- Not for your sun sign. You do for your rising sign and your Bazi hour pillar.