Devshayani Ekadashi falls in the bright half of Ashadha, the day Vishnu is said to lie down on Shesha in the ocean of milk for four months, so it also opens Chaturmas. Its katha is about King Mandhata, whose kingdom went three years without rain until the sage Angiras sent him home to keep this fast with all his people.
The coming Devshayani Ekadashi and the parana window for your city are on the Ekadashi dates page. The four months end at Dev Uthani Ekadashi in Kartika, when Vishnu wakes. Below is the story.
The katha of Devshayani Ekadashi
Yudhishthira asked Krishna about the bright Ekadashi of Ashadha. Krishna said it was called Padma, and also Devshayani, the Ekadashi on which the Lord lies down. "Brahma once told its story to Narada," he said. "I will tell it to you."
The kingdom without rain
In the age of truth there ruled a king of the Sun dynasty named Mandhata. He was a chakravarti, a king of the whole earth, and he ruled by dharma. In his kingdom the fields were full, the granaries never ran low, and no one went hungry.
Then, one year, the rains did not come. Nor the next year, nor the one after. For three years the sky stayed hard and bright. The rivers shrank to stones, the fields cracked, the cattle grew thin, and the people began to starve. No sacrifices could be offered, because there was nothing to offer.
The people came to the palace and stood before the king. "Maharaj," they said, "rain is the life of all creatures, and without it we are dying. Find a way."
Mandhata was deeply troubled. He knew that in the old view a king's dharma and his land's welfare were bound together. "If there is some fault in me or in my rule," he thought, "I must find it." He took a few companions and went into the forest, visiting one ashram after another, asking the sages what had gone wrong.
The sage Angiras
At last he came to the ashram of Angiras, a son of Brahma, and fell at his feet. The sage welcomed him and asked why he had come. Mandhata told him everything: the dry sky, the starving people, his own search for a fault he could not find.
Angiras first gave him an answer rooted in the rules of that age, one that would have meant punishing an ascetic who had done no harm. Mandhata would not do it. "I cannot hurt a man who has wronged no one," he said. "Tell me another way."
The sage was pleased with him. "Then hear this," he said. "In the bright half of Ashadha comes the Ekadashi called Padma. Go home and keep it, and have your people keep it with you. By the power of that fast the rains will come."
Mandhata returned to his capital and told everyone, from his ministers to the farmers, about the fast. When the Ekadashi came, the whole kingdom kept it together, worshipping Vishnu and praying for rain.
The clouds gathered. Rain fell, steady and generous, and went on falling. The rivers ran again, the earth turned green, and the granaries filled. The people were happy once more, and Mandhata ruled in peace.
Reading the story calmly
A three-year famine is a hard thing to picture, and the old text links the land's troubles to dharma in ways that belong to its time. In the Purana telling, Angiras first proposes harming an innocent ascetic because of his birth, and many modern retellings simply leave that out. We mention it because the king's answer is the most important line in the story: he refuses to make an innocent person pay for the kingdom's suffering. The rains come through a fast shared by all, not through anyone being blamed.
What the day is kept for
On this day Vishnu is said to begin his yoga-nidra on Shesha, and for the next four months, Chaturmas, the world is held more by prayer and restraint than by celebration. By custom, weddings, griha pravesh and similar ceremonies are put off until Vishnu wakes on Dev Uthani Ekadashi. Many people take a vow for these months: giving up a food, reading a scripture daily, eating once a day.
One well-loved telling explains the sleep through the Vamana story. When Vishnu, as Vamana, took the three worlds from King Bali, he was so moved by Bali's surrender that he promised to stay with him in Patala. Lakshmi later won him back, and he now spends these four months with Bali each year.
The mahatmya says this fast brings the merit of great sacrifices and clears all faults, and that whoever hears its story is freed of many troubles.
How it is kept
Devshayani is kept like other Ekadashis, with a fruit fast and Vishnu worship, but many homes also make a small bed for the deity, with a fresh sheet and pillow, and lay Vishnu down to rest with songs and a lamp. Vows for Chaturmas are taken on this day or on the full moon that follows. In Maharashtra it is Ashadhi Ekadashi, when the Warkari pilgrims, after walking for weeks with the palkhis of Dnyaneshwar and Tukaram, reach Pandharpur for darshan of Vitthal, and families across the state fast and sing abhangs. For the steps of the fast and parana, see the Ekadashi puja vidhi.
The Ekadashis around it
Before Devshayani comes Yogini Ekadashi, the story of the gardener Hemamali. After it comes Kamika Ekadashi, the first Ekadashi of Chaturmas, given especially to tulsi. For good hours on the day, see the choghadiya.