On Time Measurement in Ancient India

[Radhakrishna Warrier]

Here is my Facebook post on "Spring forward, fall back". 🙂

Last weekend, I was explaining to someone what “spring forward fall back” is; that we advance our clocks one hour just before spring and then, in mid-autumn, we set it back one hour to standard time.  That set me thinking – how did people tell time when there were no clocks around? I did not sit idly thinking about it.   Just did a little reading up.  So, here is the result of my online, armchair (actually couch) research on the topic and my drawing skills (or the lack of it) using the “paint” app. 

People relied on the Sun to tell time in the olden days. The ancient Chhāyā Yantra, or the “shadow machine” used the shadow cast by a gnomon to measure time.  Measurement of time using gnomons is mentioned in the hoary Vedāṅga-s (“limbs of the Veda”).   Some trigonometry is involved in deciphering time from the shadow, but our ancient astronomers handled the trigonometry quite well.  Let me add that decades ago, I made a few garden sundials but let a computer do the math and draw the dials.  That hobby project was a good exercise for my software skills as a budding engineer, although I never became a software developer but remained a hardcore hardware electronics engineer. 😊. 

Gnomons continued to be used even as late as the time of the construction of Jantar Mantar-s in different parts of India in the early 1700’s CE.  The Jantar Mantar-s incorporate giant gnomons.  The photos show the Jantar Mantar-s of New Delhi and Jaipur (Wikipedia/Wikimedia photos: https://upload.wikimedia.org/wikipedia/commons/a/aa/Jantar_Mantar_Delhi_27-05-2005.jpg , and https://upload.wikimedia.org/wikipedia/commons/9/9a/Jaipur%2C_India.jpg).  The gnomons are the big, triangular structures seen in the photos. The “Jantar” in Jantar Mantar is from Sanskrit “yantra” meaning machine or mechanism.  Mantar is Sanskrit “mantra” meaning sacred words, magical incantations, calculation, etc.  So, Jantar Mantar can mean mystery machine, or more prosaically, mechanism for measurement [of time].  

How do you tell time when the Sun is behind clouds, or when it is night?  Various types of water clocks, such as the Nālikā Yantra and the Ghaṭikā Yantra were in use from the very ancient times.  Nālikā means a tube.  The Nālikā Yantra tells time based on the outflow of water from the tube through a narrow outlet near its bottom.   “Ghaṭikā” means a small pot or a bowl.  The Ghaṭikā Yantra consists of a vessel of water in which floats a small bowl with a hole in the bottom.  Time measurement is based on when the bowl gets filled up enough to sink.  Interestingly, a unit of time of 24 minutes duration (one-sixtieth of a day) is called both “nālikā” and “ghaṭikā” after the instrument used for measuring it.  Ghaṭikā (or its alternate form ghaṭī) became ghaḍī in Hindi while nālikā became nāẓhika in my mother tongue. 

Ancient astronomical works like the Sūryasiddhānta mention Rēṇugarbha (sand vessel) as an instrument for measuring time. This can be considered an ancestor of the hourglass.  The hourglass in the shape we know today came in wide use much later, probably by the 13^th century CE.  Mechanical clocks started appearing from the 15^th century CE. 

The water clock was the basic mechanism for some of the complex astronomical instruments developed by ancient Indian astronomers.  āryabhaṭa (476 – 550 CE) constructed an interesting machine to demonstrate the daily rotation of the earth.  It worked on the principle of the tubular water clock.  In his mechanism, a wooden globe representing the Earth completes one full rotation in 24 hours, and the tubular water clock that drives it shows the time on the tube which is graduated in nālikā-s. 

When did the concept of “standard time” arise?  In India, in ancient times, the standard time used to be based on the meridian (longitude) of the city of Ujjayini (modern Ujjain.)  Like Greenwich being the prime meridian of today, the meridian of Ujjayini was the prime meridian of ancient India.  Till even a hundred years ago, the Indian pañchāṅga (religious calendar) used to be prepared with reference to the meridian of Ujjayini.  Ancient Indian astronomers calculated fairly accurately the difference in time between Ujjayini and far-flung places like Romaka (Rome) and Yavanapuri (“the city of the Greeks”).  

Here is for further reading on ancient Indian instruments for time measurement: 

https://www.soas.ac.uk/ijjs/file136765.pdf 

https://insa.nic.in/writereaddata/UpLoadedFiles/IJHS/Vol29_2_3_YOhashi.pdf 

https://insa.nic.in/writereaddata/UpLoadedFiles/IJHS/Vol28_3_1_YOhashi.pdf 

Happy “spring forward” after three weeks, and happy spring after four weeks! 😊 

 

[Sudarshan HS]

Namaskara Radhakrishna ji,

On this..

Measurement of time using gnomons is mentioned in the hoary Vedāṅga-s (“limbs of the Veda”).

.. I am curious to know of the reference in Vedangas for this. (The शुल्बसूत्राणि do mention the use of शङ्कुः but my understanding is that it is only to determine the directions, and not for the measurement of time.)

There was a recent post about another (older?) technique used in the measurement of time in Ancient India. You may find it interesting https://groups.google.com/g/bvparishat/c/TdoTQ5Y15kc/m/nyz-FZwXAAAJ

Regards,

Sudarshan

[Radhakrishna Warrier]

Dear Sudarshan ji,

Your paper on akshara as the basic unit of time measurement is quite interesting.  I am yet to read it in full.

Regarding mention of gnomon in Vedanga-s, I based my remark on the references mentioned in the attachment.

Regards,

Radhakrishna Warrier

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From: bvpar...@googlegroups.com <bvpar...@googlegroups.com> on behalf of Sudarshan HS <sudar...@gmail.com>
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Subject: {भारतीयविद्वत्परिषत्} Re: On Time Measurement in Ancient India

 

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[Rupali Kavishwar]

http://hdl.handle.net/10603/206224

Please check above link

Regards

Dr. Kavishwar Rupali

Assistant professor (sanskrit) 

GVISH, Amravati

[Sudarshan HS]

Radhakrishna ji,

I have seen the Yukio Ohashi paper presents the shadow-based time measurement from the (so called) आथर्वणज्यौतिषं sequenced along with that of शार्दूलकर्णावदानम् ।

And I see you have taken this as a Vedanga, which I had not considered earlier. I am curious to know if this book was traditionally considered as a Vedanga text ?

Incidentally, the editor of the मूलम् of the आथर्वणज्यौतिषं text, Bhagavad Dutta of Lahore (1924) thought otherwise. I quote from his introduction -

"At the end of the work the writer calls this text by the name of "आत्मज्योतिषम्" XIV.II. I have, however, given it the title of Atbarvaņa jyotişa, as in harmony with the already known Arca jyotişa and the Yajuşa jyotişa's.

.. Nothing can be said with definitness on these points. Concerned only with the Atma jyotişa for the time being, as we are, we can say, that although mainly agreeing with type (a), it still shows a small difference, nowhere else to be found.

How arose this difference is a question for the astronomer to settle. We can only say that the present text is related more to the Dharmasastras, than to jyotişa proper.

.. this Atma jyotişa, compiled according to the notions of his own age, which may be very recent. The text of this Atma jyotişa is not very old may also be in ferred from another fact. Atma jyotişa VII. 6 says : 

ज्योतिःशाखप्रयुक्तानां कर्मणां फलदं भवेत् ॥

These jyotişa treatises are very recent. Hence the work quoting them, cannot be very old. Again Atma jyotişa IX.1 states:

अल्पग्रन्थं महार्थं च प्रवक्ष्यामि भृगोर्मतम् ॥

The context shows that here also the neo-Bhrguism is referred to and not the old one. All these things put together strengthen the view that the treatise is not a very old one."

Link to the book https://archive.org/details/atharvanajyotishaedbhagavaddattamlbdms_958_z/mode/1up

Regards,

Sudarshan

[Radhakrishna Warrier]

Thank you Rupali ji, it was quite informative.  Although the language is Marathi, I was surprised that I could understand a good part of it.  Because the script is Devanagari, I could easily read it.   The many Sanskrit words made understanding easier.  Deviating a little from the topic of this thread, Sanskrit tatsama and even tadbhava content in Indian languages increase their mutual intelligibility.  Contrast this with Urdu.  Urdu at the common man's level is fairly intelligible for me.  But when it is spoken formally, as in TV and news, I cannot understand even half of it.  Even when widely used, easily understood Sanskrit-tadbhava Hindustani words are available, formal Urdu uses Persian and Arabic words in their place.  Nowadays the trend is to discard even Persian words and use Arabic instead ("Allah Hafiz" instead of the widely used "Khuda Hafiz").  And this makes Urdu still harder to understand.

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From: bvpar...@googlegroups.com <bvpar...@googlegroups.com> on behalf of Rupali Kavishwar <kavishwar...@gmail.com>
Sent: Saturday, February 20, 2021 8:48 PM
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Subject: Re: {भारतीयविद्वत्परिषत्} Re: On Time Measurement in Ancient India

 

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