Quote Originally Posted by senthilkumaras
dear sirs,
what mr.sudhama said is right for the most part except few:
We find marking of Tamizh seasons in Tholkappiyam as Perumbozhuthgal', each year divided into 6 seasons, each containing 2 seasons.Tholkappiyam mentions ilavaenil at ciththirai and vaikaasi[spring in april and may];but at present spring in Tamizh Nadu is in thai and maasi[january and february];which means there had been a shift in the positions of star constellations from the time of this record in the first Tamizh grammar book (and passed on from number of generations of masters and students upto the age of writing down of Tholkappiyam nool) to the present day - the aries(aadu iyal-mesha with aswini as first monthstar) constellation had moved from Tamizh spring day -january to april now;
That is:

Spring starts always at January 14 in Tamlzh Naadu;
The source of Tholkaappiyam says Aries(Mesha) constellation was usually seen at the start of Spring--Jan 14;
Presently Aries is seen as the evening star by April 21;

So we understand that January14 is the start of spring in Tamil Nadu geographically;and hence the New Year was and should be on Januar14 .
You may ask why Tholkaappiyam mentioned that springtime was during Chiththirai and Vaikaasi.It was because at the time of writing the script for Tamizhl grammar the Chiththirai star was seen as the evening star in the present January month.But over thousands of years the celestial positions of stars moved away{still moving--the scientists call this phenomenon "the red shift of stars" it is an Astronomical fact.}
Tholkapiyam may have been a rewritten version of an earlier grammar work { Agaththiyam or another ancient work- 100's of years even prior to the Tholkaappiyam era}
in the colloqial documentation style of the then present time.

Then how did the New year celebrations then changed to April 14! It was because in the later centuries of the 3rd Koodal Academy the Chozhar kings and the people were celebrating the INDIRA VIZHAA{Cilappadhigaaram} with so much fervour and cultural values for 1 month from chithirai pournami to the vaikaasi pournami that even after the 1 month-long festival was forgotten the auspice remained and in due course converted into the New year day celebration as a relic of the past.
Regarding star names:
Purananooru names the star signs upon the death of Mandaranjeral Irumborai.
Aadu Iyal-mesha rasi{Iyal-Rasi}
azhal kuttam-anusham
thalai meen-mirugaseerisham
nilai meen-the north star
thol naannmeen-moolam. etc.
and many more.
Ther is no mentioning of present prevailing Sanskrit names for Raasi and Year and STAR names.
So, the present Sanskrit names in Tamil Kaalakkanidham came from the mingling of {"akilabharatha koottam"} North Indian and THE South Indian astrologers some time later than 250 C.E. {end of the 3rd Koodal} (perhaps during the 11 th to 15 th centuries).
The main factor of Tamilian Calendar is the SUN... which is the Royal-planet ruling over... not only all the other Eight planets...

...but also the central-force keeping the whole universe under equilibrium and balance of varying operations of one and all the celestial bodies in the space... astronomically too.

The Tamil year duration has been reckoned as 365.25 days, the time taken by Earth for one cycle around the Sun, the Central-pivotal-force supreme.

The date of entry of Sun into Mesha(aries) house... which is its location of EXALTED STATUS (Uccha)... falls on or about April-14 every year...

..which has been taken as the first day of the year as well as the Month Chiththirai....linking Moon position also with it. So to say the Pournami falls on Chiththirai star-day in the month of Chithirai, as is the basis for all other months too. I have elaborated on this point with full details, in my last posting

The Sun's Entry-time on the first day of Chithirai month is taken as the Zero-degree....the starting point for one circle of 360 degrees... along the course of all the 12 houses(Each of 30 degrees)

So the Tamil-calendar is the best one comparatively in the world... Scientifically and by Religious aspects too....as I had already justified.

Right from ancient days...Tamil-culture extols the Sun-planet highly. And the Sun was worshipped as Supreme God by Tamilians.

Silappadhikaaram... praises and prays the Sun-God as NJAAYIRHU POATRUDHUM.