Onam is an ancient festival which still survives in modern times. Kerala rice harvest festival and the Festival of Rain Flowers, which fall on the month of Chingam, celebrates the Asura King Mahabali annual visit from Patala the underworld. Onam is unique since Mahabali has been revered by the people of Kerala since prehistory.The King is so much attached to his kingdom that it is believed that he comes annually from the nether world to see his people living happily. It is in honour of King Mahabali that Onam is celebrated. The deity Vamana, also called Onatthappan, is also revered during this time by installing a clay figure next to the floral carpet Pookalam .The birthday of Sri Padmanabhan, the presiding Deity of Thiruvananthapuram, is on the Thiruvonam day in the month of Chingam. Thiruonam day is the most important day of Onam. In Onam 2014 Thiruvonam date is September 7.
Onam mythology may have been devised as a political allegory/tool where by the subjects could remind the rulers about an Ideal King and a welfare state. Onam songs mentions many of the modern social/economic indicators of a Welfare State including Crime rates, Child Mortality rates etc. Rulers may also have promoted it as it may have served as an indicator/barometer of the popularity/unpopularity of their Governance policies. The beauty of the festival lies in its secular fabric. People of all religions, castes and communities celebrate the festival with equal joy and verve. Onam also helps to create an atmosphere of peace and brotherhood by way of various team sports organised on the day.