Significance
Durga Puja is the grandest festival of Bengal and eastern India, celebrating Goddess Durga's victory over the buffalo-demon Mahishasura. It marks the homecoming of the mother goddess with her children Lakshmi, Saraswati, Ganesha and Kartikeya.
It is a UNESCO-recognised cultural heritage of humanity.
Rituals
The main days run from Shashthi (Bodhon) through Saptami, Ashtami (Sandhi Puja), Navami and Dashami. Artistic pandals house elaborate idols; devotees offer anjali, dhunuchi dance and bhog. On Vijayadashami the idols are immersed (Bisorjon) amid Sindoor Khela.
How the date is fixed
The principal worship spans the sixth to tenth tithis (Shashthi–Dashami) of Ashwina Shukla paksha, within Sharad Navratri.