Mass celebrations of the 10-armed goddess Durga take over West Bengal for five-plus days. People flock into the thousands of Puja pandals (temporary structures, some of them extremely grandiose, housing Durga images) erected around the state, and there's a great deal of drumming and loud music, masses of coloured lights, even worse traffic jams than usual and a pervasive happy atmosphere.
At the end of it all the Durgas are ceremonially paraded to nearby water bodies and pushed in. Banks and offices may close for up to a week. Some years the festival starts in late September. It's celebrated as Dashain in the Himalayan foothills.