Vivaswat Saptami is observed on the seventh day during waxing phase of moon (Shukla Paksha) in the Ashada month. In 2015, the date of Vivaswat Saptami is July 23. The day is dedicated to the worship of Lord Surya. The Hindu Sun God, Lord Surya, is also known as Vivaswat.
The name Vivaswat is found in the Bhagavad Gita and was a powerful deity during the Vedic period. The name Vivaswat was later replaced by the name Surya and the deity also underwent some transformations.
Special pujas and rituals dedicated to Lord Surya are held on the day. Vivaswat Saptami rituals are more popular in western and southern parts of
. The Manu of the present period, Vaivaswata, is the son of the Vivaswat and is regarded as the founder of Ayodhya India
Another popular day dedicated to Lord Surya is the Ratha Saptami and is observed in the Magh month (January - February).