In 1884, Greenwich became universally accepted as the prime meridian, the international standard for 0° longitude from where all world time is calculated. Before that, Ujjain was considered the central meridian for time in India. Even today, wherever you may be born, when a panchang or horoscope as per the Hindu almanac is drawn up, it is always based on Ujjain time (roughly 29 minutes behind IST).

Abhinandita Mathur
The sundial or Samrat Yantra at the Vedshala, an observatory in Ujjain.
The sundial or Samrat Yantra at the Vedshala, an observatory in Ujjain.

Perhaps the best place to get a firsthand experience of Ujjain’s timekeeping techniques is the Vedshala (Observatory), now called the Government Jiwaji Observatory. We got there early, and as the call of peacocks rent the morning air, observatory guide Piyush Nikam deconstructed for us Ujjain’s obsession with time.
As per the Surya Siddhanta, a 4th-century astronomical treatise, Ujjain is geographically situated at the precise spot where the zero meridian of longitude and the Tropic of Cancer intersect. This is why it was considered the navel of the earth, and is called the “Greenwich of India”.

Abhinandita Mathur
Nadi Valay Yantra at the Ved-shala, an observatory in Ujjain.
Nadi Valay Yantra at the Ved-shala, an observatory in Ujjain.

On a large globe outside the Ujjain Vedshala we see Ujjain’s location pinpointed on the Tropic of Cancer. The Tropic of Cancer is significant because, as the earth revolves around the sun, this latitude marks the northernmost position at which the sun can be seen directly overhead. The Tropic of Cancer crosses the spire of Mahakal Temple in Ujjain, as it does the Somnath Temple in Gujarat. This imaginary line is also said to pass through Ujjain’s temple of Mangalnath, considered in Hindu cosmogony to be the birthplace of Mangal (Mars) and the closest point from Earth to Mars, explained Piyush.

The origins of this observatory are interesting. It was built between 1725-30 by Maharaja Sawai Jai Singh II of Jaipur, while he was the governor of Malwa. According to legend, in 1719, Jai Singh witnessed a heated debate in the Mughal court of Muhammad Shah, on how to make astronomical calculations to determine an auspicious date when the emperor could start a journey. Jai Singh, who had great knowledge of mathematics, architecture, and astronomy, felt the country needed to be educated on the subject. The Sultan asked him to build an observatory along the lines of the one in Samarkand built by Timur’s grandson Ulugh Beg. Recognizing Ujjain’s geographically significant location, Sawai Jai Singh created the first of his vedshalas here, even before the ones at Jaipur, Delhi, Mathura, and Varanasi were built.

Ujjain’s tryst with time is not coincidental. Long before this observatory was built, Ujjain was a leading centre for astronomy and mathematics in ancient India. The Surya Siddhanta provides one of the earliest known descriptions of standard time in India. Postulating a spherical Earth, the book describes the prime meridian or zero longitude, as passing through Avanti (Ujjain), and Rohitaka (Rohtak) in Haryana.

According to the Jyotisha vedanga, an ancient Indian text on astronomy, keeping time was essential to the knowledge of planetary positions, which were crucial for forecasting an auspicious day or time for Vedic rituals. In ancient times, astronomers like Varahamihira, Brahmagupta, and Bhaskaracharya among other luminaries, also made Ujjain their home. Additionally, it was here in Ujjain that the legendary king Vikramaditya drove away the Sakas and started a new era, the Vikram Samvat or the Ujjain calendar, around 58–56 B.C.

We were lucky to have a bit of sunshine on our visit, and our guide explained the functionality of each instrument in chaste Hindi. Thankfully, the information panels in English made it easy for us to follow.

This observatory measures time and altitude, determines eclipses, and studies the motions and orbits of planets. All the yantras (instruments) work on the principle of casting shadows.

Abhinandita Mathur
PiyushNikam, the guide, explains the complexities of timekeeping at the Vedshala
PiyushNikam, the guide, explains the complexities of timekeeping at the
Vedshala

Shankhu Yantra is a vertical gnomon (part of a sundial that casts a shadow) on a circular platform that calculates the length of the day. The Karka rekha (Tropic of Cancer), Makar rekha (Tropic of Capricorn) and Bhoomadhya (Equator) are marked by lines, and the gnomon’s shadow signals the equinoxes and solstices.

Samrat Yantra or sundial tells the time. A long flight of steps in the middle of the instrument casts a shadow on two walls on either side. The upper planes of the walls are parallel to the axis of the Earth, which is tilted at 23 degrees and 27 minutes with respect to its orbital plane.

Digansha Yantra calculates the altitude or distance from the horizon of any celestial body and its azimuth, or angular distance from the east or west measured along the horizon. It helps to gauge which planet is transiting from which nakshatra (celestial house) to another and its distance from Earth.

Nadi Valay Yantra calculates whether a celestial body is in the northern or southern hemisphere. Constructed in the plane of the equator, it has a northern and southern disc. These are illumined by the sun for six months each according to its position in the sky.

Bhitti Yantra or the transit instrument, is unique to Ujjain’s Vedshala. It measures the zenith distance of any celestial body with respect to Earth.

Taramandel The small planetarium (taramandel) has 20- and 30-minute shows for visitors on planets, stars, constellations, and galaxies.

In 1923, the Ujjain observatory was renovated by Maharaja Madhav Rao Scindia of Gwalior. Astronomical studies are still conducted here and an ephemeris, a journal showing the daily speed and position of the planets, is published annually.

The sun was climbing higher in the sky as we said goodbye to Piyush. He suggested we come back again on 21 June, the day of the summer solstice. “12:29 se 12:30 ke beech, ek minute ke liye aap ki khud ki parchhayi aapka saath chhod degi,” he said. (For one brief minute, your own shadow will forsake you).

The Information

Where: Govt. Jiwaji Observatory, Chintaman Road, Jabsinghpura, Ujjain
Contact: 0734-2557351
Email: segjivobsujj@mp.gov.in
Website: www.jiwajiobservatory.org
Hours: Open sunrise to sunset
Entry fee: Adults ₹10; students ₹5; foreigners ₹100; children under 6 years free; guide free with admission.
Planetarium shows: 11 a.m. to 4.30 p.m. every 30 minutes (minimum 10 people per show). Fee: Adults ₹20; children ₹10; foreigners ₹100.

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