Today, 23 July 2015 is Vivasvat Saptami. Vivasvat Saptami is an auspicious day dedicated to worship Lord Sun (Surya Bhagawan).
It is believed as the first appearance day of Vivasvat Manu, the descendent of Lord Surya. Worshipping the Prathyaksha Parameshwara (Surya Narayana swamy) on this day gives the devotee better health and prosperity.
Vivasvat Saptami is observed on Shukla Paksha Saptami in Ashad month.
As per Hindu Astrology, the time period or Kalachakram is divided into certain Manvantaras. Swayambhu Manu is the first Manu and the Hindu progenitor of mankind. Current Manu is Vaivasvata Manu and the name of this Manvantara Avatara is Vamana.