The four months of yog-nidra
From the Devshayani Ekadashi of Ashadha Shukla, Bhagwan Vishnu had lain in yog-nidra upon Sheshanag in Ksheera-sagara, with Ma Lakshmi at his feet and the devas standing in silent watch. Through the whole of Shravana, Bhadrapada, Ashwina, and now approaching the end of Kartika, no marriage had been solemnised on earth, no upanayana thread had been tied, no new house had been entered. The rishis had spent these months in intensified sadhana; the earth had rested; even the rivers had grown quiet in their inner currents.
The awakening at brahma-muhurat
On Kartika Shukla Ekadashi, at brahma-muhurat, the devas gathered around the Ksheera-sagara. Brahma began the Vedic Prabodhini-suktas; the Sapta-rishis surrounded Vishnu chanting the Purushasukta; Sarasvati played the veena at his head. Ma Lakshmi placed her hand gently upon his heart. Bhagwan Vishnu smiled in his sleep, drew one long breath, and opened his eyes. The devas raised their conches; the ocean itself rose in salutation; and upon the distant earth every rooster crowed at once.
Tulsi Vivah on Dwadashi
On the following day, Dwadashi, the shastra prescribes Tulsi Vivah — the ceremonial marriage of the Tulsi plant, who is Vrinda-devi, to a shalagram, who is Vishnu himself. Every household plants a tulsi kyari, decks it with a red chunri, sugarcane arches and haldi, and performs the wedding with the same mantras as any human vivah. From that Dwadashi onwards, every shubh karya of the year resumes across Bharatavarsha; marriage-seasons open, invitations go out, priests are booked.
The vrat and its promise
Devotees observe this Ekadashi with the most joyful vrat of the year: fast the day, keep jagran with continuous kirtan, offer sugarcane, banana and til to the tulsi at midnight, and hear the Prabodhini-katha. The shastra promises that on this single night Bhagwan Vishnu, freshly awakened, grants direct darshan to whoever chants his name with unmixed bhakti — and blesses the year to come with dharma, artha, kama, and finally moksha.
"The most joyous Ekadashi of the year. Its vrat marks the resumption of all shubh karya, opens the marriage season, and grants Vishnu's direct darshan for the year ahead."