The great churning of the Divine Ocean, for Amrita, by Gods and Demons is considered to done on this day. Shiva has consumed the poison on the same day. Hence Shaivates consider this Ekadasi as the Nanjunda Ekadasi.
Hindus observe this day as day of prayer and fasting.
According to legend, whoever dies on this day goes directly to heaven without passing through the cycle of reincarnation.