Chhath Puja is a Hindu festival dedicated to the worship of the sun god, Surya, and Chhathi Maiya, a revered goddess linked with the lunar calendar. Celebrated primarily in the states of Bihar, Jharkhand, Uttar Pradesh, and some parts of Nepal, Chhath Puja is marked by elaborate rituals that extend over four days. The festival usually falls in October or November, six days after Diwali, depending on the lunar calendar. The rituals associated with Chhath Puja are observed with great devotion and involve a series of preparations, prayers, and offerings to the sun god. Devotees fast, maintain cleanliness, and engage in various rituals to seek the blessings of Surya for the well-being, prosperity, and longevity of their families.

The first day of Chhath Puja is known as Nahay Khay, during which devotees take a holy dip in rivers or other water bodies. Following the bath, they prepare traditional vegetarian meals, which are consumed only once a day, marking the beginning of a stringent fast. 

The second day is called Kharna, and it involves fasting without water for the entire day. The fast is broken in the evening after offering kheer (sweetened rice porridge) and fruits to the setting sun. The Prasad, or offerings, are then distributed among family members and friends. 

On the third day, devotees observe a day-long fast, abstaining from food and water. They gather at riverbanks or ponds and offer a series of rituals known as Sandhya Arghya to the setting sun. This involves standing in the water, facing the sun, and offering fruits, thekua (a traditional sweet), and other items as a gesture of reverence.

The final day of Chhath Puja, known as Usha Arghya, is observed at sunrise. Devotees return to the water bodies, facing the rising sun, and perform the rituals of offering water, milk, and fruits. The Chhathi Maiya, believed to be the sister of Surya, is also worshipped during these ceremonies. Chhath Puja is characterized by its simplicity, austerity, and the profound connection it establishes between nature and the worshipper. The rituals are observed with meticulous precision, emphasizing purity of mind and body. The setting sun and the rising sun are particularly significant, symbolizing the cycle of life, energy, and renewal.

The festival has a communal aspect, bringing together families and communities. Women, in particular, play a central role in the observance of Chhath Puja, taking on the responsibility of meticulous preparations and ensuring the rituals are carried out with utmost devotion. The significance of Chhath Puja extends beyond religious boundaries, and the festival has become a symbol of cultural identity, unity, and respect for nature. It is not only observed in its traditional heartland but has also gained recognition and participation in various parts of India and among the Indian diaspora around the world.

Chhath Puja is a sacred and traditional Hindu festival that celebrates the sun god and is marked by four days of rigorous rituals and devout observance. It is a festival that underscores the profound connection between humans and nature, emphasizing purity, austerity, and the cyclical nature of life. As families come together to observe Chhath Puja, it not only strengthens cultural ties but also fosters a deep sense of devotion and gratitude towards the life-giving force of the sun.