Portrait of a Indian female. Chatt is the holiest Hindu festival of people in Bihar and Jharkh and the state in India and extends to four days. During the thanksgiving celebrations of Chatt Puja, people gather on the banks of the River Ganges to bathe in its sacred water, pray and make ritual offerings to the Sun God. In Hinduism, sun worship is believed to help cure a variety of diseases, including leprosy, and helps ensure the longevity and prosperity of family members, friends, and elders. Chatt Puja is a highly elaborate festival noted for its impressive display of colorful costumes, music, singing and extravagant rituals. Kolkata, West Bengal, India.