Chhath is an ancient Hindu Vedic festival historically native to Bihar-Jharkhand and Eastern Uttar Pradesh of India and the Madhesh of Nepal. The Chhath Puja is performed to thank Sun for bestowing the bounties of life on earth and to request the granting of certain wishes. Chhath puja dates and muhurat are given below.

The Goddess who is worshipped during the famous Chhath Puja is known as Chhathi Maiya. Chhathi Maiya is known as Usha in the Vedas. She is believed to be the beloved younger wife of Surya, the sun god. This is the only parva which signifies rising sun as well as setting sun both.
Chhath puja dates and muhurat:
Chaturthi
Nahay Khay
Sunrise at 06:28
Sunset at 17:54
Panchami
Lohanda and Kharna
Sunrise at 06:28
Sunset at 17:53
Shashthi
Chhath Puja, Sandhya Arghya
Sunrise at 06:29
Sunset at 17:53
Saptami
Usha Arghya, Parana Day
Sunrise at 06:29
Sunset at 17:52

Women worship the Sun God
The first day of Chhath is known as Nahay Khay. The holy dip in water body, especially in river Ganga, is taken on this day. Women folks who observe Chhath take only single meal on this day. PTI file photo

Woman devotees put vermillion on eachothers' forehead
The second day of Chhath is known as Kharna. On this day fasting without water is observed from the sunrise to the sunset. The fast is broken just after sunset after making food offering the Sun God. PTI file photo

Devotees perform Chaiti Chhath Puja rituals at river Ganga
A full day fast without water is observed on the third main day of Chhath Puja. Offering Arghya to the setting Sun is the main ritual of the day. It is the only time of the year when Arghya is given to the setting Sun. The third day fasting continues throughout the night. PTI file photo

Woman gives 'Arghya' to rising sun
On the fourth and final day of Chhath, Arghya is given to the rising Sun and it is known as Usha Arghya. The 36 hours long fast is broken after given Arghya to the Sun. PTI file photo
Muhurat Courtesy: drikpanchang