This is the most important festival in Assam and occurs three times a year. In April, it is called Rongali or Bohag Bihu, in October November Kati Bihu, and in January, coming with Makara Sankranti, it is called Bhogali Bihu. Thus the festival celebrates the three seasons of spring. It is in thanks giving or a prayer with the hope of having a good harvest to the earth, sun, cattle, and the implements to which a farmer owes his living. Rongali or Bohag Bihu, celebrated in April. It is celebrated for three days. On the first day called Goru Bihu, cows are worshipped. In the morning, their feet are washed; horns and hoofs are painted various colors and are adorned with flower garlands. The cows are driven through the village followed by a troupe of musicians, to a near by pond or river, here they are given a ceremonial bath. And they are let loose for the day. On returning from the river, the younger people seek the blessings of their elders. Everyone bathes with special paste called mati mah.

On the next day, called Manuh Bihu, special dishes made of flattened rice, curds, and jaggery and sweets are prepared and eaten. The third day is called Gosain Bihu and is dedicated to the worship of deities. On all three days of the festival, troupes of musicians and dancers visit houses and perform the Bihu dance in the open. Young men and women participate in this rhythmic dancing, which was traditionally reserved for unmarried girls and was also a ground for many marital alliances.
Kati Bihu is a one-day festival in autumn in the month of Kartik. It occurs just after the fields have been sow. The festival is hence also called Kangali Bihu, the poor or bankrupts Bihu. After a ritual bath, people keep a day – long fast and pray to the tulasi plant. In the evening, earthen lamps are lit and placed near the basil and banana plants, granary, the backyard and the fields. Prayers are also offered at these places to protect the seedlings from any damage or danger and also for a good crop.
Bhogali Bihu is celebrated in Magha immediately after the winter harvest. The word ‘bhogali’ comes from bhoga, which translates to ‘feast’, and the festival is essentially one off eating and merry making after a good harvest. Every villager contributes to this feast. Special structures called meji, made of hay from the newly harvested field, banana leaves and green bamboo stalks, are constructed in the fields.