Thursday, April 15, 2010

Tamil New Year in Chithirai : Explained

In response to popular demand (one person asked), I have written a quick post on the meaningfulness of celebrating Tamil New Year's day on the First day of Chithirai month, which is the Sidereal Vernal Equinox day. I had written a similar post in Tamil few years back and hence the English version now.


day and night are of equal duration. dates are slowly variable across centuries. currently equinoxes occur around March 22 - Spring Equinox and Sept 22 - Autumn Equinox


days when sunlight is longest (Summer Solstice - June 22) and shortest (Winter Solstice - Dec 22)

How so?

The Earth revolves around the sun at an inclination of abt 23 degrees. So Sun appears to move up or down thru the year. One revolution is ofcourse a year.


Spring Equinox - sun is directly above the Equator - day and night times are equal on March 22. After this day, Sun starts 'going' north.

Summer Solstice - Sun is farthest from the Equator in the northern direction. its now directly above the Tropic of cancer. Tropic of Cancer passes thru Central India. So summer is intense. Naturally the longest day of the year occurs on June 22nd. Sun now turns back and travels south.

Autumn Equinox - Sun has come back to to the top of Equator. day and night times are again equal on Sept 22.

Winter Solstice - Sun is farthest from the Equator in the Southern direction. Farthest from India. Its now directly above the tropic of capricon in the Indian Ocean. Sun is far, so winter is cold. The shortest day of the year occurs on Dec 22nd.

Note: all these seasons are w.r.t to Northern Hemisphere. In the southern hemisphere, the seasons will be opposite.

Why shud new year be celebrated on Equinox?

There is no necessity, but many cultures do. A day with equal day-night seems a good candidate. Especially most parts of India celebrate on the Spring Equinox. The Roman calendar also began in March with September (Septa - 7), October (Octa - 8), November (Nova - 9), December (Deci - 10) and ending in the last Month February (less days). But the New Year was moved to January for political reasons. Chinese New Year is supposed to be mid-way between Winter Solstice and Spring Equinox. Hence between Jan end to mid Feb.

Equinox is on March 22, why does Tamil New Year occur on April 14?

Becos Tamils (along with malayalis, punjabis, assamese etc) follow Sidereal year and not tropical year. Sidereal is calculating the movement of the Sun vis-a-vis Earth by noting the postion of certain stars. i.e. with respect to fixed positions on the sky and not just the position of the sun. This fixed year is the Sidereal year.

From around April 14, Chitra star (one point of reference) is visible. The Sun is in the Aries (Mesham) zodiac constellation. If we strictly go by the position of the Sun, that year is tropical year. So currently, tropical Equinox is March 22 and sidereal equinox is April 14.

So then, is Ugadi (Telugu/Kannada new year) the correct observance of Spring Equinox?

Not really. They follow a luni-solar calendar. i.e. their months take both the Sun and the Moon into consideration. Their Ugadi (new year) day keeps moving w.r.t the lunar month closer to the Spring Equinox (March 22).

What is Zodiac?

Its just a way of dividing the sky into 12 equal parts and taking a constellation to name it. When the Sun appears within/closer to a constellation of stars, Sun is supposed to be present in that Zodiac. There is no reason to be alarmed about Astrology w.r.t to Zodiac signs.

I don't believe the position of the stars in any year with respect to their position at your time of birth has any relevance. In short, astrology is mostly non-sense. But Zodiac is just a position of the Sun in the sky. So no harm in using the Zodiac signs in conversation.

Coming back, why can't we celebrate New Year on Pongal?

Becos Pongal is already celebrated on Winter Solstice. Sun is turning north from Tropic of Capricon. So its gonna come back to Northern hemisphere, bringing warmth with it. Hence we celebrate. We can as well celebrate both Spring Equinox (as new year) and Winster Solstice as Pongal. More the merrier.

Isn't Pongal the Tamizhar Thirunal (Tamil people's day)?

non-sense. Winter Solstice is celebrated in almost all the states of India. Everywhere its the harvest festival. The joy of Sun starting the northerly journet bringing Spring. And in many states rice-moong dal Pongal (aka Kichidi) is the specialty. This day btw is called Makara Sankranthi becos the Sun travels from the Makara line (Tropic of Capricorn) towards north from this day.

Why can't we have Thiruvalluvar Year and Thiruvalluvar Day as reference for New Year?

How do we know Thiruvalluvar was born on that year? What evidence? Its mere conjecture by Maraimalai Adgigal (aka Vedachalam) that the author of Thirukural was born 31 years before Christ. A dubious assertion which shud not be taken seriously.

And Thiruvalluvar day was selected by Karunanidhi as the day after Pongal, which incidentally is based on the same Tamil calendar which picks Sidereal Vernal Equinox day (Chithirai 1) for New Year. An arbitrary year and arbitrary day as Thiruvalluvar's birth day is quite silly. That day cannot be the start of our year.


rajesh said...

Excellent explanation, i fully agree wtih the facts you have given.

i am thinking of ways to make people to know this facts.

altered egos said...

Ah i like the explanation for makar sankranti and a few others :) lot of info thanks

Rajiv said...

Have been following your blog for quite sometime... should say its interesting....

Balaji said...


Subbu said...

Its very informative posting.. thanks.

Anonymous said...

Sadly, winter solstice is around December 22 and Uttarayana starts from this day. The calendar made in those days did not realize the long term slow changes that happen. It is quite possible that the Indian calendars were accurate regarding the Uttarayana being around Jan 14th. But the calendar did not account for the small changes. Whereas the Gregorian calendar accounts for these small changes once every 100 years. The change in the solstice day is supposedly one day in about 70 years. The difference between the actual solstice and our celebration day being about 25 days, the calendar is about 1750 years old. And indeed the Indian calendars are that old or older.

But stupidly superstitious as we are, we celebrate Makara Sankranthi on Jan 14th, almost 25 days after Uttarayana starts.....

Balaji said...

true, i have throughout the post used dec 22, mar 22 etc and not jan 14 and april 14 etc.

however, it should noted that the Indian National Calendar which was adopted by the Union Government after independence required Indian traditional calendar makers to correct the year to start on March 22. The Rashtriya Panchangam published by the government, i believe starts on March 22 too.

Anonymous said...

Nice post. I have a question about your statement "sidereal equinox is April 14." How can there be such a thing as a sidereal equinox? The equinox is based on seasons and therefore the tilt of the Earth. So a tropical year goes from vernal equinox to vernal equinox (or summer solstice to summer solstice, etc.). If we choose to use a sidereal year, we follow star positions, not seasons. It's a bit like using British system vs. metric sytem. You can't have a sidereal equinox any more than you can have a metric mile. The fact that Chithirai corresponds with Aries and that the vernal equinox was in Aries a couple thousand years ago suggests that Indians borrowed this system from the Greeks (or earlier from the Babylonians or others). Pisces today and Aries then are only significant on a tropical calendar. If you're interested in sticking to a sidereal calendar, you shouldn't care which constellation goes first.

Balaji Chitra Ganesan said...

Thanks for your informative comment.

My knowledge of sidereal year is only superficial. So I have no reason to disagree with your comment.

As a layman, I would be happy to start the tamil calendar on Vernal Equinox (March 20 in 2015?). If the Gregorian or Julian year is starting in January assuming the birth of Christ to be close (or some other reason) to winter solstice, I have no qualms about that. I also enjoy the fact that Christmas in Russia is in early January for example! I cherish the historicity of those people celebrating their New Year near Winter Solstice.

Similarly, I feel Tamils (and most Indians) have historically celebrated New Year around vernal (spring) equinox. The fact that a pre-christian era calendar, Roman? one also started in March is another happy coincidence.

For all these reasons, I feel a govt (which has no business interfering on such matters, since it uses Gregorian calendar anyway for its business) changing the Tamil New Year, on a whim, to the Pongal day, was an act of vandalism on our history.

Anonymous said...

Thanks for your response, Balaji. This is the guy that posted on Oct. 16th. It doesn't feel right commenting anonymously while you have fully disclosed who you are. My name's Bhasker Moorthy. I teach astronomy at a college in the Chicago area. I left India when I was eleven and so I'm only vaguely aware of the "official" change to the Tamil Calendar. But I plan to look into Indian calendars and other aspects of ancient Indian astronomy in detail over the next couple of years. If you're interested in discussing that sort of thing, we can be in touch. I'll send you a friend request on Facebook.

Anonymous said...

Beautiful explanation.. Thank you :D

Prasad Senji said...

Hi Balaji / Bhasker

You guys are the knowledgeable ones, so I have this question.

What is the Tamil name for equinox and solstice ? In fact, I came to this blog searching for that.

Another point I want to add is regarding Bhasker's previous comment that we are nowadays celebrating Makar Sankarathi almost 25 days after the solstice on 22 Dec - I think the most important reason for celebrations may be the harvest. Our farmers have traditionally followed certain planting and harvesting seasons, so, during current times, even though the solstice would have passed several days before, the harvest may still be happening during the same period of the year. So, the Sankrathi/Pongal is continued to be celebrated at around 14 Jan.I am not a farmer but an Engineer. So, pardon me if I am wrong.


Prasad Senji


Balaji Chitra Ganesan said...


Yes, your explanation sounds reasonable.

Equinox in Tamil is Vizhu. Same name as the festival famously celebrated in Kerala. Bihu in Assam is the same word. Though bihu comes from Sanskrit, I have read a linguist credibly argue that Vizhu might be a Dravidian loan word to Sanskrit.

I'm not sure what's the true Tamil word for solstice. Some people use utharayanam and datshinayanam, which are obviously loaned from Sanskrit.

Anonymous said...

Can you suggest a simple elementary book on equinox/solstice for understanding

Anonymous said...

Bhasker here again. I hadn't checked this blog in a couple of months.

For concepts such as equinox and solstice, Wikipedia is perfectly adequate. There are also free astronomy textbooks (and videos, podcasts...) available online such as

And yes, Pongal would have occurred during the winter solstice a couple thousand years ago. It has drifted by the same number of days on the tropical calendar as Tamil New Year has. Since I'm also not a farmer, I don't know how suitable a date it is (or was) for harvest. If it is now, it certainly won't stay that way for ever since it's constantly drifting by 1.4 days per century.

Richa Sharma said...

Make this New Year the memorable one by celebrating it with Top of the Hill on the most beautiful hill station-Mussoorie, India.

Nandini Sree said...

gud info.Here is an interesting Tamil calender app i found
here is the link