Durga Puja, observed in the Hindu calendar month of Ashvin or September-October, according to the Gregorian calendar, is a festival celebrated annually in different states across India. This is the major festival for Bengalis across the world, and is an occasion marks the battle of good over evil. Spread across 10 days, it signifies the birth of Durga with the blessings of the gods, as a collective energy, to fight the demon king Mahishasura, who was blessed with immortality and could not be killed by any god or man, which is why a goddess had to accomplish the feat. This year Durga Puja will begin on September 20 and will end on September 30.
It is unclear how and in which century the origination of this festival took place but it is believed that Durga, a symbol of feminine strength, appeared to mark an end to negative forces in society symbolised as Mahishasura. This festival is celebrated for a duration of 10 days, running parallel with Navratri. Starting from the sixth day of the Navratri to the ninth, huge pandals are opened for the public, as a congregation space for anyone to come and take part in the celebration. This multi-day festival features elaborate stage decorations, dance performances, processions and recitals.
According to folklore, Durga would take a different form each of the days to fight the demon, and finally on the tenth (Dashami), or last day, of Durga Puja, she would kill him, and everyone would bid her farewell. Prayers are offered to the deity before bidding her goodbye till the next year. It is after this that the idols are immersed in water, known as Visarjan, as it is believed that the goddess travels back to heaven via the water channels.