Pongal is a multi-day Hindu harvest festival celebrated by Tamils. The festival is celebrated over three or four days, which are named Bhogi, Thai Pongal, Mattu Pongal and Kaanum Pongal, beginning on the last day of the Tamil calendar month of Margazhi, and observed on consecutive days. Thai Pongal is observed on the first day of the Tamil calendar month of Thai and usually falls on 14 or 15 January in the Gregorian calendar.
According to tradition, the festival marks the end of winter solstice, and the start of the Sun's six-month-long journey northwards called Uttarayana when the Sun enters Capricorn. It is dedicated to the solar deity Surya and corresponds to Makar Sankranti, the Hindu observance celebrated under various regional names across the Indian subcontinent.