Wikipedia
Bwisagu
Bwisagu or Baisagu is one of the most popular seasonal festival of the Bodos of Assam. In Assamese language it is called as Bihu. The Bodos call this popular festival as Baisagu, which means the start of the new year. Baisagu is a Boro word which originated from the word "Baisa" which means year or age, ang "Agu" that means starting or start. Hence, Baisagu, the starting time of the year or age. This Baisagu festival is observed at the starting part of the first month of the Assamese and Bengali year(first week of the month of Bohag or Baisakh).