The twelfth lunar day
Sanskrit 'dvadasha' (twelve): the tithi immediately following Ekadashi.
An Ekadashi fast is properly broken (Parana) on Dvadashi morning, within a specific prescribed window of time.
Meaning, Origin, Fasting and Parana
From the Brahmavaivarta Purana, truthful King Harishchandra regains his kingdom, wife, and resurrected son by observing Aja Ekadashi.
The sacred story from the Brahmanda Purana of the Amla tree (Indian Gooseberry) created from Lord Vishnu's tears, granting salvation even to a sinful hunter in Phalguna Shukla Paksha.
Freeing a King's Spirit
The divine katha of Harishayani Ekadashi marking the beginning of the four sacred months of Chaturmas when Lord Vishnu rests upon Sheshanaga.
The divine katha from the Skanda Purana marking the awakening of Lord Vishnu after four months of Yoga Nidra, concluding Chaturmas and beginning Tulsi Vivah.