Chhath Puja is an Illustration of Surya and Sanskriti
Organiser   13-Nov-2018
Chhath Puja is dedicated to the worship of the Surya Dev and his wife, Usha. Hindus celebrate the festival by following a rigorous routine that lasts four days. It includes fasting for over 36 hours which also requires abstinence from drinking water. It also requires devotees to take a holy bath in a water body, and offer prayers to the rising and setting sun.
Worshipping the Surya from time immemorial has been the ethos of Bharat 
It is believed that the celebration of Chhath puja may predate to the ancient Vedas, as the rituals performed during the puja are similar to the ones mentioned in Rig Veda, in which the Surya is worshipped.
According to legend, the rishis were known to worship the Surya and remain without food as they would obtain their energy directly from the most significant source of energy. Another legend associates it with Lord Rama. According to ancient texts, Sri Ram and Maa Sita had kept fast and offered prayers to the Surya, in the month of Kartika in Shukla Paksha, once they returned to Ayodhya after 14 years of exile. From then on, Chhath Puja became a significant and traditional Hindu festival, which is celebrated with zeal and zest every year. The festival also finds mention in the Mahabharata. Draupadi, the wife of the Pandavas, was an ardent devotee of Surya Devata, who on the advice of sage Dhaumya performed similar rituals.
Manifestation of Sanskriti
Chhath is both a festival and a cultural ritual. The association of Surya Devta and the river bank in the festival, and the incorporation of fasting as a way to purify the soul puts forth the inherent idea of Sanskriti through it.
Devotees offering arga to Surya Dev 
The centrality of Surya in the civilisational continuity of Bharat is so bold to be missed! The existence of Sun temples throughout the country, the cycle of harvest festivals being determined by the movement of the sun, and significance of the sun in daily activities such as Yoga and food habit are remarkably seen across the Bharatiya Sanskriti.
Konark temple in Odisha, also known as the Black Pagoda and the ‘Chhath’ festival in North India symbolises the deep reverence Indians across millennia have for the Sun. The reverence is so deep that the Yogic Asanas targeted for various body parts are combined in the form of ‘Surya Namaskar’ to pray to the Sun. The sun has played a huge role in Indian art, culture, and spirituality.
Before human species discovered fire, the only sources of light were the sun and the moon. Sun was the antithesis to darkness and evil and a symbol of virtue and truth. This concept was shared by most ancient cultures including Indians. Occasional droughts and famines led by prolonged summers were seen as the wrath of Sun God. He was revered and feared as well. Gayatri Mantra from Rig Veda is dedicated to Vedic Sun Deity Savitar.
Overall, to argue, as it is done today that Chhath is a North Indian, or Bihar-centred festival is wrong. This festival is one among many which accentuate the significance of Surya in our everyday life. The sun along with the river bank has been at the centre of our cultural ethos. And therefore, Chhath is a celebration of the same!