Vrat rules and puja vidhi of Parivartini Ekadashi
Lord Vishnu swaps his sleeping position under the cosmic ocean as he continues to be in the state of Yoga Nidra.
The fifth Ekadashi Tithi during the holy-Chaturmas period in the Hindu calendar is Parivartini Ekadashi. It is one of the most important days for the devotees of Lord Vishnu. It is the day when the fifth avatar of Lord Vishnu, Lord Vamana emerges on Earth during the Satyuga.
The devotees worship Lord Vishnu as well as Vamana Avatar. Since then there is a difference between the traditional Hindu and Gregorian calendars, the date keeps changing every year.