The harvest festival of Tamil Nadu, Pongal festival, generally falls in the Tamil month of Thai (January), and this year it will be celebrated on 14th January. It is regarded as the oldest festival in India as its origin can be dated back to the Sangam Age (200 B.C. to 300 A.D). Initially, it was celebrated as a Dravidian Harvest festival and was called "Thai Niradal." On the day of the festival, all unmarried girls got together and prayed for an agricultural prosperity. Goddess Katyayani, one of the nine avatars of Goddess Durga, was worshiped during Thai Nadal.<br> <br> Then during the reign of Pallavas, Pongal was celebrated as ‘'Paavai Nonbu". During that time, the young girls offered prayers to God for yearly rain, bringing prosperity for people. Throughout the month of Margazhi, they did not drink milk or any milk products. They even avoided applying oil to their hair. All these traditions paved the way to the Pongal festivity of today.<br> <br> Pongal is celebrated for days, and each day has its own significance. Read on to know more about how each day of Pongal is celebrated.