Bihu is a set of three important non-religious festivals unique to the Indian state of Assam – 'Rongali' or 'Bohag Bihu' observed in April, 'Kongali' or 'Kati Bihu' observed in October, and 'Bhogali' or 'Magh Bihu' observed in January. The festivals present an admixture of Indo-Aryan, Tibeto-Burman and Austroasiatic traditions entwined so intricately that it is impossible to separate them—festivals which are uniquely Assamese to which all communities of Assam had contributed elements. The Rongali Bihu is the most important of the three, celebrating spring festival. The Bhogali Bihu or the Magh Bihu is a harvest festival, with community feasts. The Kongali Bihu or the Kati Bihu is the sombre, thrifty one reflecting a season of short supplies and is an animistic festival.