Chhath Parva, also called as Chhat Puja is another festival celebrated in Nepal on October/November month, just right after the Tihar festival. Chhat is the main festival of Maithila region or in Maithili culture which is located in Nepal and India. Mithila is also known as Videha, Tirhut, Tirabhukti and Mithilanchal. It is believed that this festival is mentioned in both religious books of Hindus, Mahabharat and Ramayan. It’s a geographical and cultural region in Nepal and India with natural boundaries of rivers and hills. The region is bounded by the Mahananda River in the east, the Ganga in the south, the Gandaki River in the west and by the foothills of the Himalayas in the north. Seven major rivers flow through Mithilanchal, which are: Mahananda, Budhi Gandaki, Gandaki, Kosi, Bagmati, Kamala and Balan.
Chhat Festival lasts for 4 days which starts from Kartik Shukla Chaturthi to Kartik Shukla Saptami of Hindu calendar. Some people called as a Surya Sasthi for Chhat festival. Surya means sun in native languages. Actually the Sun is worshipped during the festival for the prosperity considering the sun as the god or source of every energy. It can also be said that the festival is a thanks giving day to Lord Surya (the sun) for sustaining life on this earth. The festival includes taking holy bath at ponds or Rivers, fasting, standing and worshipping to the sun and offering Prashad and Argh to the Sun, in both occasions – at the time of rising and setting.