chhat puja

Chhath (Dala Chhath) is an ancient Hindu festival dedicated to Surya, the Hindu Sun God, Surya, also known as Surya Shashti. The Chhath Puja is performed in order to thank Surya for sustaining life on earth and to request the granting of certain wishes. The Sun, considered the god of energy and of the life-force, is worshiped during the Chhath fesival to promote well-being, prosperity and progress. In Hindu mythology, Sun worship is believed to help cure a variety of diseases, including leprosy, and helps ensure the longevity and prosperity of family members, friends, and elders.
Chhath puja is performed on Kartik Shukala Shashti, which is the sixth day of the month of Kartik in the Hindu Calendar, exactly 6 days after Deepawali. Chhath, being an arduous observance, requiring the worshipers to fast without water for more than 24 hours, is tougher to undertake in the Indian winters.

Chhath 2010 date

10 November (Day1: Naha Kha)
11 November (Day2: Kharna)
12 November (Day3: Sanjhiya Arghya)
13 November (Day4: Paran-Bihaniya Arghya)

Nahakha (literally, bathe and eat):

On the first day of Chhath Puja, the devotees take a dip, preferably in the holy river Ganges, and carry home the holy water of the river Ganges to prepare the offerings. The house and surroundings are scrupulously cleaned. The parvaitin allows themselves only one meal on this day.
                                             देओब्रत    कुमार मोलन