Jyotisha
ज्योतिष — the eye of the Veda
Vedic astronomy · Calendar · Time-keeping
Jyotisha (ज्योतिष, from jyotis, "light" or "heavenly body") is the Vedanga concerned with the luminaries of the sky and the measurement of time. Of the six Vedangas it is traditionally called the eye of the Veda, because it lets the Vedic householder and priest see when to act: Vedic rituals were tied to the new and full moon, the solstices, the seasons and particular nakshatras, and all of these had to be predicted in advance. The oldest surviving text of the discipline, the Vedanga Jyotisha attributed to Lagadha, is essentially a manual for keeping a ritual calendar in step with the Sun and Moon.
Over the following two thousand years Jyotisha grew into a sophisticated mathematical astronomy. The Siddhanta texts of Aryabhata, Brahmagupta, Bhaskaracharya and the Kerala school computed planetary positions, eclipses and the length of the year, and developed trigonometry, algebra and infinite series along the way. Alongside this astronomy grew Samhita (omens, seasons and natural phenomena) and Hora (horoscopic astrology). Today the most visible product of Jyotisha is the Panchangam, the almanac that fixes festival dates and daily timings for hundreds of millions of people.
Explore Jyotisha
Daily tools, reference articles and the history of Indian astronomy.
Panchangam & City Timings
पञ्चाङ्ग
The five limbs of the Hindu day — Tithi, Vara, Nakshatra, Yoga and Karana — with sunrise-based timings for 25 Indian cities.
Festivals
उत्सव
Dates of Hindu festivals and vratas — Ugadi, Navaratri, Deepavali, Shivaratri, Ekadashis — computed from the lunar calendar.
Rahu Kalam
राहु काल
The daily period traditionally avoided for new beginnings, with Yamagandam and Gulika Kalam, for each weekday and city.
Choghadiya
चौघड़िया
The eight day and eight night divisions — Amrit, Shubh, Labh, Char, Udveg, Rog and Kaal — popular in western India.
Muhurta
मुहूर्त
The 30 muhurtas of the day, Brahma and Abhijit Muhurta, and how auspicious times are chosen for ceremonies.
The 27 Nakshatras
नक्षत्र
The lunar mansions of the sidereal zodiac, each 13°20′ wide, with their stars, deities and ruling planets.
The Navagrahas
नवग्रह
Surya, Chandra, Mangala, Budha, Guru, Shukra, Shani, Rahu and Ketu — the nine grahas of Indian astronomy.
Kala — Vedic Time
काल
Units of time from the nimesha and ghati to the muhurta, yuga, manvantara and kalpa, with modern equivalents.
Calendar Systems
संवत्
Amanta and Purnimanta months, solar and lunisolar years, Vikrama and Shaka eras, and the 60-year Samvatsara cycle.
Regional Calendars
प्रादेशिक पञ्चाङ्ग
How Telugu, Tamil, Malayalam, Bengali, Odia, Gujarati and North Indian calendars differ — and what they share.
Astronomers & Mathematicians
आचार्य
Lagadha, Aryabhata, Varahamihira, Brahmagupta, Bhaskaracharya, Madhava and Nilakantha Somayaji.
Jyotisha & Astrology
होरा
The three skandhas of Jyotisha, rashis, bhavas and dashas — an educational introduction to a traditional belief system.
The five limbs of the Panchangam
The word panchanga means "five limbs". Every Hindu almanac lists these five elements for each day, and all of them are derived from the longitudes of the Sun and the Moon:
- Tithi — the lunar day: the time the Moon takes to gain 12 degrees on the Sun. There are 30 tithis in a lunar month, 15 in each paksha (fortnight).
- Vara — the weekday, running from sunrise to sunrise and named after the seven visible grahas.
- Nakshatra — the lunar mansion occupied by the Moon, one of 27 equal divisions of the sidereal zodiac of 13°20′ each.
- Yoga — one of 27 divisions obtained from the sum of the sidereal longitudes of the Sun and Moon.
- Karana — half a tithi, so that there are 60 karanas in a lunar month, drawn from a set of 11 names.
To these the almanac adds the lunar month and paksha, the solar month and its sankranti, the 60-year Samvatsara name, sunrise and sunset, and timings such as Rahu Kalam and Abhijit Muhurta. Our daily Panchangam presents all of them for every date, and the city pages recompute them for local sunrise.
The three branches of Jyotisha
Classical writers such as Varahamihira describe Jyotisha as having three skandhas (branches): Siddhanta or Ganita, mathematical astronomy; Samhita, the study of omens, weather, seasons and collective events; and Hora, the casting and interpretation of horoscopes. Vedangam concentrates on the astronomical and calendrical side — the part that can be checked against the sky — and explains the astrological traditions in an educational, neutral way on our astrology page.
Jyotisha among the six Vedangas
Jyotisha is one of six auxiliary disciplines that grew up around the Vedas. Together they teach how to pronounce, perform, analyse, interpret, scan and time the sacred texts. Read about the others: Shiksha (phonetics), Kalpa (ritual), Vyakarana (grammar), Nirukta (etymology) and Chandas (metre).