What is the date today? A simple question, but with a complex answer.
The story of calendars is the story of human civilization itself. The millenial 1 article by Amartya Sen tries to disentangle fact from fantasy in the history of calendars. Never an easy task in history, especially hard in the keeping of time itself.
Today I will describe a simple answer to this question devised by the medieval astronomer-mathematicians of Kerala, where many mathematical techniques useful for the accurate calculation of time were discovered first, between 13th and 16th centuries C.E.. But this simple method is used by no one except scholars, the people at large preferring much more complicated systems that reflect their religious and cultural backgrounds. I will look at one of these calendars, the Kollam calendar 2.
There are (and have always been) many calendars in use in India, although civil life now revolves around the Gregorian Calendar used by most of the world. It is called the `English Calendar’ in memory of the people who instituted its use in India. But many personal and religious matters still are governed by the more traditional calendars. There is a variety of these calendars, each used for a different purpose.
This reflects the many layers of history that exist simultaneously in India, later influences not completely erasing previous ones. It is this parallelism of Indian culture, the way it seems to exist in different time streams simultaneously, that makes it so difficult to study Indian history objectively. Time is not a one-dimensional notion in Indian consciousness. Instead of a river of time, there are multiple rivers that occasionally meet and coalesce and then diverge while new streams can arise and old ones die out. There might be historical events that mark the beginning of some of these calendars, but many are lost in the mist of legend and myth.
Before delving into the calendars with direct astronomic and mathematical significance, used mainly by scholars, it is useful to look at an everyday calendar, the kind you might see in a barber shop in the interior.
A glance at this month’s calendar published on line by Deepika, a popular Malayalam newspaper already gives a window into a complex cultural history3. I use this calendar only as an example. Those published by other popular newspapers follow the same pattern. I chose the Deepika to illuminate the fact that the Catholic Church, at least by the nineteenth century, was in the business of giving away accurate calendars free, possibly to undermine the monopoly of the traditional `applied astronomers’ of Kerala.
The name of the month and dates are given in big letters; July is spelled out in English and Malayalam. The big number in each box is the date in the Gregorian calendar.
But if you look carefully you will see there are several smaller numbers in each box.These are the dates in the other calendars still in use. At the top of the page, in smaller letters, the year and month (more precisely the two months in each calendar which overlap with July) in these other calendars are given. A footnote at the bottom explains to which of these calendars each date corresponds. Lower left is the `Malayalam date’, more precisely the date according to the Kollam calendar. This was the dominant calendar in Kerala until it joined the Indian Union in the early fifties.
The top number on the right corner is the Saka date, the official calendar of the Indian Government. This calendar was adopted in 1957 by a committee chaired by M. N. Saha 4, the renowned Indian Astrophysicist. It is an adaptation of an old calendar that was widely used in North India until the Muslim conquests. Which brings us to the number at the bottom of the right corner, the date according to the Hijra calendar. This is the calendar of the Muslim world, and commemorates the flight of the Prophet to Medina. The table at the bottom gives the daily prayer times for Moslems. The square to its left is the astrological chart of planets used mostly by Hindus. All helpfully provided, for more than a century, by a Catholic Congregation!
Thus today is 28th July 2007 in the Gregorian calendar, 12th Karkadakam (Cancer) 1182 in the Kollam calendar, 6 Sravana 1929 of the Saka era, and 13 Rajab 1428 of the Hijra era. But we are not done yet.
In between the numbers at the bottom are the position and phase of the moon,which are still used for religious purposes to denote the date. It is easiest to explain the lower word. It simply counts the number of days from the new moon ( the black dot on July 14th indicates that the moon was dark that day). The next day is prathamam (first), then dwitheeya (second) and so on until July 29th which is chaturdasi (14th). The count restarts from first on July 30th, which is full moon as indicated by the white circle.
The upper word is the nakshatra, the constellation of stars (asterisms) nearest to the moon on that day. There are twenty eight of them, the Malayalam words sounding like hick mispronunciations of the more widely used Sanskrit names elsewhere in India 5.
The period of revolution of the moon is not an exact integer multiple of the period of rotation of the Earth: it is 27.3 days. Hence a 28th nakshatra (Abhijit) with an unusually short interval (about eight hours) is inserted to compensate for this. You learn the nakshatra list in school (same time as you learn the days of the week) but Abhijit is usually left out of these lists as well as in the popular calendars. It is there in the more detailed calendars used by the astronomers5.
Thus in this traditional lunisolar calendar, today is Pooradam Nakshatram of Karkkada Rashi (Month of Cancer) in the Kollam year 1182. This is the reckoning still used for Hindu religious festivals. If you make a contribution at a temple, the Priest will ask you for your name, your birth Nakshatram and your birth place : he needs to insert this into the prayer he will say on your behalf.
While the days of the lunar month have names that clearly correspond to the Sanskrit names used elsewhere, the names of the month in the Kollam calendar are possibly more familiar to Westerners. At least, if you sneak a look at your horoscope once in a while.
|Makaram||Sea-monster(Capricorn or Goat)|
Midhunum actually means a couple engaged in a sexual act; who sanitized it to Gemini(twins) in the English version of the horsocope? The meaning of Makaram is different too. Kumbham means water-pot, not water-carrier.
Although the list of months starts with Leo (close to the main festival Onam), the more traditional date for the start of the New Year is the first of Medam (the festival of Vishu). The word Vishu means `equal’ in Sanskrit; Vishudinam means equinox 6. So one might be tempted identify this festival with the spring equinox. But if that is the case, the calendar is off by 25 days. The spring equinox is on March 20 and Vishu was celebrated this year on April 15th. This does not mean that the Kollam calendar itself is inaccurate. Perhaps the early custom was for Vishu to coincide with the equinox. After it got out of sync, a corrected calendar could have been developed in which the error did not grow anymore. It would take much greater political will to lop off three weeks from a widely used civil calendar, so probably that was not done. Further study is needed to know what really happened here. Recall that when the Gregorian calendar was instituted, even with the support of a Papal Bull, there were many protests 7 over eleven days that had to cut out of the calendar.
There are attempts to date classical Indian texts based on the astronomical events quoted in them 8 . The case of the Kollam calendar is a warning against taking the words denoting religious rituals literally. The word `Vishu’ may mean `equal’ but it does not follow that the current date of celebration of Vishu is on the equinox. One needs to make sure that astronomical observation and not merely a religious tradition or mathematical extrapolation is used to date historical events.
It is a fair criticism of much of ancient Indian astronomy that it was long on calculation and short on observation. Damodara, one of the Astronomer-Mathematicians of Sangamagrama attempted to introduce a corrected system (DrkGanita-calculations based on observation) but it never quite caught on outside of scholarly circles. More on this later.
It is also not clear what event marks the beginning point of the Kollam calendar. I grew up with the tradition in Southern Kerala that it commemorates the rebuilding of the town of Kollam after a fire. However, it appears that there are other stories also going around. It could commemorate the building of a Siva temple near Kollam. It could have to do with the establishment of a Christian settlement in Kollam. It looks as if every community has its own story. Actually I can’t even tell which town called Kollam is involved. Most people assume it is the town called Kollam currently, which is at 8°53’4″N 76°35’4″E. However there is also a Kollam (Pantalayani Kollam) in Malabar and Kolhapur in Maharasthra (whose name simply means `Kollam town’) which were equally important in ancient times. The meaning of the word Kollam is lost to time 9 .
The multitude of calendars in simultaneous use-even before the arrival of foreigners- presented both a headache and an opportunity for astronomers. Many generations of them made a good living by publishing almanacks called PanchaAnga, after the five parts they contained. Quite a profitable profession, as the shrewd Benjamin Franklin realized years later in the colonial America. The various astronomical phenomena associated to time (Solstices, Equinoxes, Phases of the Moon, and the movements of the planets) had religious significance. Some, like the solstices and equinoxes were important agricultural events, to know when to plant seeds and when to harvest. Birthdays of people had to be kept track, interest on loans calculated, rent on land collected. As accurate calendars became available for free, this `applied astronomy’ has degenerated into astrology: still a lucrative profession. The astrologers are about as successful as economists in predicting the future, but even better at making a comfortable living.
In the same way that the decimal system evolved out of a need to do long calculations in astronomy, a simple system was needed to keep track of the date. Astronomers in Kerala adopted the simplest possible system to keep time: just count the number of rotations of the earth from some fixed instant in time. The original instant chosen was assigned a mythical meaning, the starting moment of the Kaliyuga, supposedly the moment that Krishna died. This is similar to the myth that the Gregorian calendar counts the number of years after the birth of Jesus. As Amartya Sen points out, such starting points are the always result of backward extrapolation. It strains credulity that accurate astronomical measurements were possible in India five thousand years ago. Even more unlikely that someone kept count of the number of days over almost two million days.
Whatever the choice of origin, the system of determining todays date by simply counting the number of rotations of the Earth from some fixed instant has a stunning simplicity. No need to think of the motion of the Sun or the Moon or of the planets. No Leap years (as in the Gregorian Calendar) , Leap months (Hijra calendar) , extra nakshatra (Abhijit) to keep track of. More importantly, no need to know the period of the revolution of the Earth or the Moon merely for the purpose of determining the date. A simple answer to a simple question. This number is the KaliDinaSamkhya, the Kali date. Alas, it is not recorded in the popular calendars, but it is listed in the “Noottantu PachaAngam” 5 (Century Almanack) . These are the kind of texts used by temple priests and such, so we are climbing one step in the ladder of technical sophistication.
So what is the date today? Today is 1865844 .
More on the applications of this simple idea later.
1. India through its Calendars Amartya Sen ; available online at http://www.littlemag.com/2000/sen.htm
This calendar is of special interest as it was the main calendar used in Kerala. It remains to be seen whether the mathematical techniques were properly used in the making of the Kollam calendar, let alone whether these techniques were transmitted to the West. It is certainly an intriguing fact that European mathematics underwent a radical transformation, leading in particular to calendar reform, just about the time that Catholic priests made contact with the scholars of Kerala. Before such a study can be undertaken, we need to understand the Kollam calendar as it is commonly used today. I hope to examine later how accurate the Kollam calendar is, what its mathematical underpinnings are. This might shed light on the issue of possible transmission of the mathematical astronomy to the West through the learned Catholic missionaries.
3. The Deepika was established in 1887 by a congregation of Catholic nuns. Just a couple of days ago it was bought by a Muslim business man, to the dismay of local Catholics. But the edition we are looking at was published well before this event. The calendar is available at the website http://www.deepika.com/calendar/. News item on Deepika available at the website http://www.catholicnewsagency.com/new.php?n=9961. Another popular calendar is made available by the Kerala Kaumudi Newspaper at http://www.keralakaumudi.com/calender2007/cal2007.pdf .
4. M.N. Saha and N.C. Lahiri, History of the Calendar (New Delhi; Council of Scientific and Industrial Research, 1992); See Saha and Lahiri, History of the Calendar (1955), pp. 252-3; S.N. Sen and K.S. Shukla, History of Astronomy in India (New Delhi; Indian National Science Academy, 1985), p. 298 as quoted by Amartya Sen, see endnote 1.
5. Nootantu PanchaAngam (in Malayalam) ed. Puliyoor Mohanan Naboothiripad, Prepared by G. V. Polikattil, Pub. by DC Books,Kotttayam, India.(2006) ISBN-81-264-1241-0 .
6. The Student’s Sanskrit English Dictionary V. S. Apte, Pub. Motilal Banarsidas Delhi (1970).
7. See the wikipedia article http://en.wikipedia.org/wiki/Gregorian_calendar; The Oxford Companion to the Year. Bonnie Blackburn & Leofranc Holford-Strevens. Oxford University Press 1999. ISBN 0-19-214231-3.
8. Subhash Kak, Archaeoastronomy and literature . Current Science, vol. 73, No. 7, 10 October 1997, pp. 624-627; available online as http://www.ece.lsu.edu/kak/science.pdf .
9. I thank M. Raghava Varrier for correcting some of my previous certainties on the origin of the Kollam calendar.
10. Although the main body of this article was written on July 28th 2007, some notes were added and some clarifying editions made to the text in the few days after that.