Going back to the Sangam Age i.e., 200 B.C. to 300 A.D Pongal had its origin. Pongal is an ancient festival of the Tamils identified with the Thai Un and Thai Niradal that were supposed to be celebrated during the Sangam Age. Pongal, a traditional Tamilian food item and is perhaps the only dish to have lent its name to a festival.
As part of the celebrations, unmarried girls of the Sangam era observed penance during the Tamil month of Margazhi (December-January).
All through this month, they avoided milk and milk products, didn't oil their hair and refrained from using harsh words while speaking. The women had their ceremonial baths early in the morning.
The image of Goddess Katyayani, which would be carved out of sand was worshiped. They ended their fast on the first day of the month of Thai (January-February). This fast was to bring abundant rains and agricultural prosperity for the country.
According to Hindu mythology, this is when the day of the gods begins, after a six-month long night. The festival is spread over four days and is the most important and most enthusiastically celebrated harvest festival of South India especially Tamil Nadu.
A special puja is performed on the first day of Pongal before the cutting of the paddy.
Farmers worship the sun and the earth by anointing their ploughs and sickles with sandal wood paste. It is with these holy tools that the newly-harvested rice is cut.
According to a legend, once Shiva asked his bull, Basava, to go to the earth and ask the mortals to have an oil massage and bath every day and to eat once a month. Inadvertently, Basava announced that everyone should eat daily and have an oil bath once a month. This mistake enraged Shiva who then cursed Basava, banishing him to live on the earth forever. He would have to plough the fields and help people produce more food. Thus, this day is associated with cattle.
Each of the three days of Pongal are marked by different festivities. The first day, Bhogi Pongal, is a day for the family. The second day, Surya Pongal is dedicated to the worship of Surya, the Sun God. Boiled milk and jaggery is offered to the Sun God. The third day of Pongal, Mattu Pongal, is for worship of the cattle known as Mattu. Cattle are bathed, their horns polished and painted in bright colors, and garlands of flowers placed around their necks. The Pongal that has been offered to the Gods is then given to cattle and birds to eat.