Chhath festival dedicated to the worship of Lord Surya or Sun God is observed a couple of days after Diwali in the Kartik month (October – November) mainly in Bihar, Terai region of Nepal and in parts of eastern Uttar Pradesh, Jharkhand, Madhya Pradesh, Bengal and Chattisgarh. The devotee observing the Chhath fast is known as Parvaitin. The Chhath fast is usually observed by women. During the four days of the Chhath rituals the Parvaitin stays away from all types of work.
Parvaitin is assisted by her husband, children and other family members in completing the four-day Chhath rituals, which involves 36-hour long fast, cooking of special food and the worship on the banks of a holy river.
A devotee becomes a Parvaitin when the mantle is passed on to her by an elderly devotee who was observing the Chhath ritual in the family.
Once a devotee takes up the Parvaitin responsibility she continues to perform the rituals annually without any break and stops only when she has identified a person capable of continuing the tradition. She then passes the tradition to the person usually from younger generation.
A Parvaitin skips the annual puja only in the event of a death in the family.