The festival of Chhath Puja is celebrated in Eastern India to worship the Sun God and to praise his virtues. It is an ancient Hindu celebration that traces its origins to prehistoric Vedic times. Along with the sun, his sister, Chhathi Maiya, is also worshipped for sustaining life on earth. Chhath Puja is held over the span of four days and is marked by various rituals, including fasting, standing in water for long periods of time at dawn and dusk, and making offerings to the Sun God and his sister.
According to the legends, the kings of ancient North India invited Maga Purohits as they were highly proficient in worshipping the sun. Since this worshipping, the Chhath Puja was originated. There is another belief amongst Hindus that Chhath Puja was celebrated in the Vedic period also, as the hymns offering prayers to the Sun God are found in Rigveda.
Mahabharata also contains some historical references to Chhath Puja. Draupadi is shown offering similar worship of Sun God in Mahabharata. According to the epic, on the advice of great saint Dhaumya, Pandavas and Draupadi performed Chhath Puja. As a result of this worship, Draupadi was able to solve many problems of Pandavas and helped them in taking over their lost kingdom.
The celebration of this festival takes place on a span of four days. This involves many rituals including fasting and isolation of the whole family of the devotee. People offer their prayers at dawn while standing in running water of a river on the last day of this festival. It is extensively celebrated in Eastern Indian states of Bihar, Bengal, Jharkhand and Odisha. It is a national festival and a state and regional holiday in many northern and eastern states.