Significance and legend
Parama means supreme, and this Ekadashi, falling in the dark fortnight of the adhika masa, is said to grant the highest merit. In the traditional account, Krishna tells Yudhishthira of a poor but virtuous Brahmin named Sumedha who lived with his devoted wife Pavitra in the city of Kampilya. Despite their poverty, they never turned away a guest, often going hungry themselves. Burdened by want, Sumedha thought of leaving to seek his fortune in distant lands, but his wife persuaded him that prosperity comes from virtue and the grace of God rather than from wandering.
The sage Kaundinya visited their home, and they served him with all they had. Moved by their humility, the sage told them of Parama Ekadashi, the Ekadashi of the dark half of the adhika month, and taught them a special five-day observance called Pancharatri. The couple followed his instructions faithfully. Soon afterward a prince visited them and, recognising their goodness, gave them a fine house, a village and all they needed. They lived in comfort and generosity for the rest of their lives and finally attained Vishnu's abode.
How Parama Ekadashi is observed
Devotees fast on Ekadashi, and some follow the Pancharatri vow of five days of restraint as taught by Kaundinya. Vishnu is worshipped as Purushottama with flowers, tulsi and lamps, and the story of Sumedha and Pavitra is read. Charity and hospitality toward guests are central to the observance. The fast is broken on Dwadashi after sunrise within the parana window, after offering food to Vishnu and feeding Brahmins or the needy.