Significance and legend
Apara means limitless, and Krishna tells Yudhishthira that the merit of this Ekadashi is boundless, removing sins like killing, slander, false testimony, and the teaching of false knowledge. The story associated with it tells of King Mahidhvaja, a just and pious ruler, whose younger brother Vajradhvaja was cruel and jealous. One night Vajradhvaja murdered the king and buried his body beneath a peepal tree in the forest. Because of his untimely death, Mahidhvaja became a restless ghost living in the tree, troubling passers-by.
One day the sage Dhaumya passed that way and, through his spiritual vision, understood the ghost's history. He freed the spirit from the tree, instructed him in dharma, and himself observed Apara Ekadashi, transferring its merit to the king. By that merit Mahidhvaja was released from his ghostly state, took a divine form and ascended to heaven. In Punjab, Haryana and Jammu the day is also observed as Bhadrakali Ekadashi, and in Odisha as Jalakrida Ekadashi.
How Apara Ekadashi is observed
Observers eat once on Dashami and fast on Ekadashi from grains and beans, many without water until evening. Vishnu as Trivikrama is worshipped with tulsi, flowers and lamps, and the Apara Ekadashi katha is read. Devotees avoid falsehood, criticism and anger during the vrata, and keep vigil at night. On Dwadashi the fast is broken after sunrise within the parana window, after feeding a Brahmin or the poor and offering food to Vishnu.