Four-day Sun worship of Bihar and eastern UP; 36-hour nirjala fast and arghya to setting and rising Sun

Chhath Puja is the great festival of Surya, the Sun God, and his sister Chhathi Maiya (Shashthi Devi, the protector of children), celebrated on Kartika Shukla Shashthi, six days after Diwali, mainly in Bihar, Jharkhand, eastern Uttar Pradesh and Nepal's Madhesh, and wherever their people live. It is one of the oldest Vedic sun rituals still practised, with no idol worship: the devotee (vratin, usually women) stands in a river or pond and offers arghya to the Sun itself. The four days in 2026 are Nahay Khay (13 Nov) — a holy bath and a single satvik meal of lauki-chana dal and rice; Kharna (14 Nov) — a day-long fast broken at dusk with rasiao-kheer and roti; Sandhya Arghya (15 Nov) — after a nirjala fast, arghya to the setting Sun at the ghat with bamboo soops full of thekua and fruits; and Usha Arghya (16 Nov) — arghya to the rising Sun, after which the 36-hour fast is broken. Legends link Chhath to Sita after her return to Ayodhya, to Karna (the son of Surya, who stood in water offering arghya daily), and to Draupadi. It is kept for children's health, family prosperity and the fulfilment of wishes, with extraordinary purity and discipline.

A 36-hour nirjala fast from after Kharna prasad until after Usha Arghya. Salt, onion and garlic are avoided throughout the four days.