Lord Shri Vishnu goes to Yoganidra for four months on Ashada Shukla Ekadashi. After this, he awakens to Kartik Shukla Ekadashi. In these four months, all the auspicious works are forbidden due to Dev Shayan. When Lord Shree Vishnu wakes up, only then any auspicious work is done. It is called Dev Uthani Ekadashi because of its awakening or elevation. Observing fast on this day is of special importance. It is said that this leads to salvation. It is also considered to be the biggest Ekadashi. This year, Dev Uthani Ekadashi is on 25th November.
Observing fast should be done on anhydrous or just aquatic substances. If there is a patient, old man, child or busy person, then only one Vela should have fasted. If this is not possible, rice and salt should not be consumed on this day. Do devotion to Lord Shri Vishnu or your presiding deity. On this day, do not eat tamasic food (onion, garlic, meat, liquor, stale food). One should chant the mantra "ॐ नमो भगवते वासुदेवाय" on this day.
Build a cane canopy, a square is built in the middle. If you want, you can place a picture or statue of Lord Vishnu in the centre of the square. Along with the square, the footprints of the lord are made, which are covered. Sugar and fruit-sweets are dedicated to Lord Vishnu. A lamp of ghee is lit, which keeps on burning throughout the night. The feet of God are duly worshipped at dawn. The sound of conch-bell-and kirtan is done. After this, the story of fasting is heard. Subsequently, all auspicious works can be started duly.