In the Indian state of Kerala, Onam is an annual cultural festival. It is the state's official festival and includes a variety of cultural activities, making it a major annual event for Keralites. Onam is a Hindu festival that honors King Mahabali and Vamana.
Onam commemorates good governance under the rule of Mahabali, a mythical king who ruled Kerala. According to legend, the devas and gods plotted to end Mahabali's reign because they were jealous of his popularity and power. They sent Vamana to earth as a dwarf Brahmin, who trampled Mahabali to patala (netherworld). Vamanan requested three feet of land from the generous Mahabali as his wish. Mahabali agreed to fulfil Vamana's wish because denying gifts to Brahmin is considered a sacrilege. Vamana measured the entire universe with his first two feet, leaving no room for his third foot. Mahabali offered his own head to place his third feet, completing the wish. However, witnessing Mahabali’s generosity, Vishnu granted the king's sole wish to visit his land and people once every year. This homecoming of Mahabali is celebrated as Onam in Kerala every year.
Based on the Panchangam, Onam is celebrated on the 22nd of the month Chingam of the Malayalam calendar, which in the Gregorian calendar occurs between August and September.