All Ekadashi have special significance in Hinduism. Devshayani Ekadashi falling in the month of Ashadh is considered extremely important. Chaturmas also begins from this day. Lord Shiva controls the universe during Chaturmas. This period of four months is called Chaturmas. During Chaturmas, auspicious works like tonsure, marriage, housewarming, land worship, etc. are not performed. By worshipping Lord Vishnu and Goddess Lakshmi with a true heart on the day of Devshayani Ekadashi, the devotee receives Akshaya Punya and happiness and prosperity increase. According to the scriptures, from this Ekadashi, Shri Hari goes to rest in Kshir Sagar and awakens on Devuthani Ekadashi falling in the month of Kartik.According to mythological beliefs, on the day of Devshayani Ekadashi, Lord Vishnu visits King Bali in Patal Lok. By observing this fast, all sins are destroyed and salvation is attained. Lord Vishnu becomes pleased and fulfills all wishes.

Dev shayan also has scientific importance.
In Sanskrit literature, the word Hari is used especially for Lord Vishnu, Sun, Moon and Air. During Chaturmas, all these major powers Sun, Moon, Air etc. become weak and the elements obtained from them become scarce in the atmosphere. Due to this, many types of changes also take place in our body and our digestive power becomes weak. Since Lord Hari is considered omnipresent in the scriptures, Satvaguna among the three qualities present in our body and Pitta among the seven major metals of the body is considered to be the representative of Lord Hari. In such a situation, this time is considered a special time for the worship of Hari and the person is advised to eat Satvik food and live a Satvik life. At the same time, due to astronomical reasons, the Sun enters Cancer and becomes Dakshinayan and the rainy season is in its youth. Cancer is an aquatic sign. In such a situation, after entering Cancer, the Sun gradually moves forward reducing its intensity. During this time, the powers of the Sun become weak.  This time is considered to be the night of the gods. It is said that during this time all the gods and goddesses go into yogic sleep. By the time Kartik month arrives, the Sun enters Libra. Devuthani Ekadashi occurs around this time. Devuthani Ekadashi is considered to be the day of awakening of the gods. From this day onwards all the religious rules are implemented again and auspicious works start again.

On Devshayani Ekadashi, Lord Vishnu’s idol should be bathed with Panchamrit and worshipped with sandalwood, incense sticks, etc. After that, as per your capacity, a bed made of silver, brass, etc. should be spread over it and a yellow silk cloth should be spread over it and Lord Vishnu should be made to sleep. Keep fast as per your faith throughout the day and meditate on God. Do not gossip or speak ill of anyone. Stay awake at night and the next day on Dwadashi, feed a Brahmin and send him off by giving Dakshina as per your capacity and then break the fast. In the house where Devshayani Ekadashi fast is observed, no tamasic food should be cooked even by mistake and meat and alcohol should not be consumed. Women should not wash their hair on Devshayani Ekadashi. Nails and hair should not be cut on Devshayani Ekadashi. Doing so is considered extremely inauspicious. By observing Devshayani Ekadashi fast, a person gets wealth, health and prosperity.  By fasting and worshipping on this day, all sins are destroyed and salvation is attained. Fasting on this Ekadashi especially provides relief from the ill effects of Saturn and brings happiness, peace and prosperity in life. It is believed that by observing this fast, one gets the blessings of Lord Vishnu and all troubles are removed.