Utthana Ekadasi, or Prabodhini Ekadashi, is observed during the waxing phase of moon in the month of Kartik (October – November). In 2015, the date of Utthana Ekadasi or Dev Prabodhini Ekadashi is November 22. The importance of Dev Prabodhini Ekadasi narrated to Sage Narada by Brahma. The divine conversation is found in the Skanda Purana. Observing this Ekadasi is believed to help in getting rid of the guilt associated with sins committed and is also a path to liberation (Moksha). Ekadasi is an important fast dedicated to Lord Vishnu.
Importance of Utthana Ekadasi
Lord Vishnu goes into sleep on the Ashada Shudha Ekadasi (July – August). He remains in deep slumber during the period and this is known as the Chaturmasa period. He wakes up on the Kartik Shukla Ekadasi and this day is also observed as Dev Uthani Ekadasi.
Utthana Ekadasi is thus when the gods (devtas) wake up after a four-month slumber. During the four-month period some Hindu communities avoid performing auspicious ceremonies. Marriages, house warming, construction of new houses are only performed after the four month period.
On Utthana Ekadasi day, an image of Lord Vishnu is drawn on the ground. Lamps are lit around it and fruits and vegetables are offered to this fresh image.
In some regions the image is covered with a big brass plate symbolizing that He is sleeping. Bhajans dedicated to Lord Vishnu is sung and he is asked to shed his sleep and wake up and bless people.
To wake the Lord, children light mustard torches at night and make lot of noise.
Other Rituals on the Day
The famous Tulsi Vivah festival is performed on the day by some communities and also on the day after Ekadasi in some regions.
The Chatur Mas period also ends with Prabodhini Ekadashi.
The famous Kartik Month Pandarpur Yatra is observed on the day.
All the normal rules associated with Ekadasi fasting are observed on the day.
Staunch Vishnu devotees observe a rigid fast on the day by skipping food and staying awake during night. Majority of the people take one meal mostly in the evening and visit shrines dedicated to Lord Vishnu.
source – http://www.hindu-blog.com/2008/11/utthana-ekadasi-dev-prabodhini-ekadashi.html