Chhath is an ancient Hindu festival historically native to the Indian subcontinent, more specifically, the Indian states of Bihar, Uttar Pradesh, Jharkhand, and the Nepalese provinces of Madhesh and Lumbini. Prayers during Chhath puja are dedicated to the solar deity, Surya, to show gratitude and thankfulness for bestowing the bounties of life on earth and to request that certain wishes be granted.
Chhathi Maiya, the sixth form of Devi Prakriti and Lord Surya's sister is worshipped as the Goddess of the festival. It is celebrated six days after Deepavali, on the sixth day of the lunar month of Kartika (October–November) in the Hindu calendar Vikram Samvat. The rituals are observed over four days. They include holy bathing, fasting and abstaining from drinking water (vrata), standing in water, and offering prasad (prayer offerings) and arghya to the setting and rising sun. Some devotees also perform a prostration march as they head for the river banks.
Environmentalists have claimed that the festival of Chhath is one of the most eco-friendly religious festivals in the World. All devotees prepare similar prasada (religious food) and offerings. Although the festival is observed most widely in the Terai region of Nepal and the Indian states of Bihar, Uttar Pradesh, West Bengal, and Jharkhand, it is also prevalent in areas where the diaspora and migrants from those areas have a presence. It is celebrated in all northern regions and major north Indian urban centers like Delhi. Hundreds of thousands of people celebrate it in Mumbai.
Chhath puja is dedicated to the sun god Surya. The sun is visible to every being and is the basis of life of all creatures on earth. Along with the Sun God, Chhathi Maiya is also worshipped on this day. According to Vedic astrology, Chhathi Maiya (or Chhathi Mata) protects the children from diseases and problems and gives them long lives and good health.
As per legends, Chhath Puja stems from the early Vedic period, where sages would fast for days and perform the puja with mantras from Rigveda.