Significance and legend
On Devshayani Ekadashi in Ashadha, Lord Vishnu lies down for his four-month yoga nidra on the serpent Shesha. On the Ekadashi of the bright half of Kartika he awakens, and the day is called Prabodhini (awakening) or Devutthana (the rising of the Lord). In the Skanda Purana, Brahma tells Narada that the merit of this Ekadashi equals that of a thousand horse sacrifices and a hundred Rajasuya sacrifices, and that a single fast and night vigil on this day destroys sins accumulated over many lifetimes.
The day also begins Tulasi Vivah, the ceremonial marriage of the tulsi plant to Vishnu in the form of Shalagrama. The Puranas tell of Vrinda, the chaste wife of the asura Jalandhara, whose devotion made her husband invincible. When Vishnu broke her vow to allow Jalandhara's defeat, she cursed him to become a stone, the Shalagrama, and herself became the tulsi plant. Vishnu blessed her that she would be worshipped with him forever and that he would wed her each year after his awakening.
How Devutthana Ekadashi is observed
Devotees fast and in the evening awaken the Lord with the sound of conches, bells and songs, often drawing his footprints and placing sugarcane, water chestnuts, seasonal fruits and lamps before him. Tulasi Vivah is performed on this day or within the following days up to Kartika Purnima, with the tulsi plant dressed as a bride. In Maharashtra, Kartiki Ekadashi draws pilgrims to Pandharpur. With the end of Chaturmasa, the season of weddings and other ceremonies reopens. The fast is broken on Dwadashi after sunrise within the parana window.