Pongal Festival
Probably one of the oldest "thanksgiving " festivals is the ancient festival of Pongal. This festival has been traced back to 200 BC and is celebrated on the 14th of January. That date is chosen because it marks the beginning of the sun's movement North, called Uttarayana, in India. The festival also marks the end of the farming season and a period of rest for those hard worked farmers! Bells, drums, and cymbals all make their noise to announce the beginning of the 4 day festival. The first day, Bhogi, is the day where old clothes are thrown out and new clothes put on to symbolize beginning a new life. The second day is called Pongal, the word "pongal" means "to boil over" and that is part of the tradition. To symbolize the abundance of the harvest, people make a porridge with freshly harvested rice and milk in a new clay pot and they let the porridge boil over the edges of the pot. The porridge, also called pongal, is then eaten by everyone- including the animals! There are rituals performed over rice in the temples and offerings of sugarcane, vegetables and spices are given to the gods. Once the food has been offered, the people then eat it in the belief that their sins will then be forgiven. The third day is a fun one, it is called Mattu Pongal, and that day is to give thanks and celebrate the animals that are so helpful to the farmers. 
The cows and buffaloes that help to plow the fields are given a spa day! After a bath, their horns are polished and painted pretty colors and they are decorated with necklaces of flowers. Their living areas are cleaned and they are given special treats to eat. On Mattu Pongal it's good to be a cow :) That leaves the fourth day, Kanum Pongal, where families go out and spend the day together picnicking or visiting others. They snack on sugarcane, another symbol of a plentiful harvest. There are songs and dances traditionally performed during this time and if you are interested in learning some please check out this Pongal Festival website.I borrowed a poem from the website- a kind of prayer .
Pot rice to Sun God
Sugarcane to cow and ox
Sweet rise to you and me
Good milk to friends and family
-M. Narayanan
I wish you all good milk :)