Dev Shayanee Dwaadashee Vrat
(Chap 70) Krishn said - "Mahaaraaj, Now I tell you about Govind-Shayan named Vrat, Kati Daan, Samutthaan and Chaaturmaasya Vrat." Yudhishthir asked - "Bhagavan, What is this Dev-Shayan? When Devtaa sleep then how this world moves on? Why do they sleep, and how this Vrat is done?"

Krishn said - "When Soorya enters in Mithun Raashi (Gemini), one should make the idol of Madhusoodan sleep and when Soorya enters in Tulaa Raashi (Libra) then he should wake Him up. One should neither make Him sleep or wake up by any other method. In Aashaadh Maas, on the 11th day of Shukla Paksh, one should keep fast and make the idol sleep on a white bed. First bathe it with Panchaamrit, clothe it and worship it with this Mantra. (see the Mantra on p 453) After making Him sleep, one should vow to keep control on his tongue and follow other rules. Thus Bhagavaan sleeps for four months of the year.

Now you listen to the rules of this period -
Who leaves jaggery (sugar) becomes king having sweet speech in next life
Who leaves oil, takes beautiful body.
Who leaves mustard oil, he has no enemy.
Who leaves the oil of Mahuaa attains Saubhaagya.
Who leaves flowers etc he becomes Vidyaadhar in Swarg.
Who practices Yog he attains Brahm Pad.
Who leaves any one kind of food, bitter, sweet, salty, hot; he is never born in low level species.
Who leaves betel leaf, enjoys various pleasures and has sweet throat.
Who leaves Ghee, he gets beauty and Siddhi.
Who leaves fruits, becomes intelligent and gets many sons.
Who eats leafy vegetables becomes sick.
Who eats uncooked food becomes clean body.
Who leaves oil massage gets close to Kuber.
Who leaves milk, yogurt and buttermilk attains Go Lok.
Who eats only cooked food gets long lived children.
Who sleeps on floor, he becomes devotee of Vishnu.
Who eats only once in the 6th Prahar of the day he goes to Swarg permanently.
Who leaves water for two Prahar, he never falls sick.

(There are many other rules described here.)

During these months, marriages, Yagya etc are not performed. In the month which has no Sankraanti, (Mal Maas) no activity related to Devtaa and Pitar should be performed.

In Bhaadrapad Maas, on 11th day of Shukla Paksh, Vishnu's Kati Daan is done. Kati Daan means "to change the side" - Vishnu changes His side. Mahaa Poojaa should be done this day.

Now you listen to the reason of this Vishnu Shayan. One time, Yog Nidraa pleased Hari by her Tapasyaa and prayed - "Please give me a place in your body parts." Then I found that my whole body is covered with Lakshmee's all body parts, so I gave her a place in my eyes and said - "You will be in me for four months. So Yog Nidraa dwelled in my eyes. Whenever I sleep on this Shesh Shayyaa (bed) in Ksheer Saagar, at that time Lakshmee massages my both feet and the waves of Ksheer Saagar washes my feet. Who lives with many rules during these four months, he lives in Vishnu Lok for the whole Kalp.

Dev Utthaan
Vishnu wakes up in Kaarttik Maas, on the 11th day of Shukla Paksh. Wake up Bhagavaan with this Mantra. (see the Mantra on p 455 - Yajur Ved 5:15) After he has woke up, all religious activities in the world start. Give a round to Bhagavaan on a chariot in the night. Decorate the city with lamps and wake the whole night. Next day, 12th day, worship Vishnu Bhagavaan, do Havan, and feed Braahman with various dishes. Offer him Laddoo made with Ghee, honey, Jaggery etc. Feed 11, 10, 8, 5, or 2 Braahman to one's capacity, worship them and give them the left thing (which you did not consume for four months) and Dakshinaa. Later one should eat himself also along with that that thing which you have left for four months. This is Dharm. Whose Chaaturmaasya Vrat is completed without any obstacle he never takes rebirth. Who does fasting on both days, the day Bhagavaan sleeps and the day Bhagavaan wakes up, he gets good Lok.