Bohag Bihu or Rangali Bihu also called Haat Bihu (Assamese: ব’হাগ বিহু, Hindi: बोहाग बिहू) (seven Bihus) is a festival celebrated in the state of Assam, India seven days after Vishuva Sankranti of the month of Vaisakh or locally 'Bohag' (Bhaskar Calendar). It unites the population of Assam regardless of their social standing and it promoted diversity amongst all. The three types of Bihu are Rongali Bihu, Kongali Bihu, and Bhogali Bihu. Each festival recognizes a different agricultural cycle of the paddy crop. Rongali Bihu celebrates the beginning of the Assamese New Year on April 13, according to Hindu calendar and the sowing season of rice. During Rangali Bihu there are 7 pinnacle phases all named: Chot Bihu, Raati Bihu, "Goru Bihu", Manuh Bihu, Kutum Bihu, Mela Bihu and Chera Biha.
A group of Bihu dancers
Chot Bihu (চ'ত বিহু): This is the second day of the month of Cheitra. On this day, unmarried youths freely exercise Bihu songs and dances at either an open place, field, tiniali, or a naamghor bakori (yard of community prayer hall) till uruka (one day before Rongali Bihu). That is also called Bali Husori.
Raati Bihu (ৰাতি বিহু): The is the first night of month of Cheitra till uruka night performs the Raati Bihu. It is now obsolete. Many years ago it was recognized all over Assam especially in Chowdang villages. Only females could participate in Raati Bihu. If a male wanted to participate, he could take on the role in this celebratory role playing as pepa or buffalo hornpipe. Respectively this could only be done from the distance. An essential musical instrument of this phase was the bholuka baahor toka. This is a split bamboo musical instrument. Raati Bihu was performed beneath a big tree or in an open field illuminated by burning torches. It was quite popular that region.
Garu Bihu (গৰু বিহু): Bihu is an agricultural festival of Assam. Rural people of Assam greatly depend on cattle. The last date of Cheitra month or the day of Sankranti, the first day of Rongali Bihu dedicated to cattle, is called Garu Bihu (Bihu for cattle). That day, early morning all cattle of the village are brought to a water source like a pond, river or deep open non-plugged cultivation field etc. The cattle are washed with a combination of ; maah-halodhi (black gram and turmeric paste), whipped dighloti (litsea salicifolia, a plant with long leaf), makhioti (flemingia strobilifera, a plant with flower like soft plastic butter-fly) and throwing pices of lau (bottle gourd) bengena (brinjal). People sing the following passage: "Dighloti dighal paat, maakhi marru jaat jaat; lau khaa bengena khaa, bosore bosore bardhi jaa, maare haru baapere horu toi hobi bor bor goru" . This is roughly translated as :
"with long leaf of dighloti, we kill different types of flies; eat bottle gourd eat brinjal, and grow year to year; your mother is small father is small, you be bigger one". After washing cattle the remaining branches of dighloti-makhioti and lau-bengena chak etc. are hung on the roof of the house of cattle. Village people, wander and collect exho ebidh haak (101 types of vegetable), they also collect amlori tup (larvae of weaver ant, Oecophylla smaragdina), bind betel leaf plant, give soil on bamboo plant root, and many other symbolic harvest related rituals. There is also time to have an egg fight, also known as Kori Khel, Paakha Khel andkoni-juj. There are several other types of games to keep the celebration going till the end of the day. In the evening the cattle return in a parade type concession. There is burning rice bran to create smoke. The cattle are dressed and tethered with new ropes and wearing as garland a collection of different kinds of leaves, aromatic oils have been massaged into the whole body and horn and after the ceremonial walk back home, they are then feed pitha (Assamese sweets) while they are fanned with a handheld fans.
Manuh Bihu (মানুহ বিহু): The first date of Vaisakh month is Manuh Bihu (Bihu for Human). In the early morning, baths with maah halodhi, put on new dress and lit chaki at Gohai Ghor (household prayer place). Then bow the elder at the family. It is a tradition giving Bihuwan or Gamusa as a gift and wearing that day.
Kutum Bihu (কুতুম বিহু): The second date of Visakh is Kutum Bihu (Bihu for kinfolk). That day people visit to friends, relatives without formal invitation.
Mela Bihu (মেলা বিহু): Mela Bihu is open for all. That day people can freely meet each other. Friends & relative visits their relatives. There is no bar to see gos tolor bihu. In older days, King and his staff came out to bihutoli to see bihu. It is the base idea of recent organised Bihu Melas or Bihu functions.
Chera Bihu (চেৰা বিহু): It is the finishing day of Rongali Bihu. It is also called Bohagi Bidai, Faat Bihu etc. In the different places Assam, people celebrate it differently. In the Western Assam it is also called haat haak tula bihu (collecting seven types of vegetable). That day women collect vegetables along with singing song. Many places people exchange their pithas.