Ravinarayan Ekadashi vrat (Narayan Gyaras) is a highly meritorious Ekadashi vrata. In 2016, Ravinarayan Ekadashi date is July 15. It is observed on 11th day of Shukla Paksha (bright half) of Ashad Month.
Ravinarayan Ekadasi is popularly referred to as Shayana Ekadasi, Devsayani Ekadasi, Ashadi Ekadasi and Harivasar Gyaras.
It is believed on this day; Lord Vishnu goes into cosmic sleep (Yog nidra). It also marks the beginning of Chaturmas Vrata, four holy months in Hinduism.