Boisabi Festival in Rangamati/Khagrachhari/Bandarban
Boisabi is the collective name for the Chittagong Hill Tracts' mid-April new year season, combining Chakma Biju, Marma Sangrai and Tripura Baisu into one umbrella term. Rather than one event, it describes several distinct community festivals sharing water-throwing, flower-floating and boat-racing traditions across Rangamati, Khagrachhari and Bandarban within the same short window.
Boisabi is a name built from pieces of three other festival names: Bi from Chakma Biju, Sa from Marma Sangrai, and Bi again from Tripura Bizu, also called Baisuk, stitched into shorthand for a shared new year season across the Chittagong Hill Tracts.