Vaikuntha Ekadasi

As per Vishnu Purana, fasting on Vaikunta Ekadashi is equivalent to fasting on the remaining 23 Ekadashis of the (Hindu) year.

Lord Shri Mahavishnu opened the gate of Vaikuntam (his abode) for two demons in spite of they being against the Lord. They also asked for the boon that who ever listens to their story and see the image of Lord coming out of the door (called Dwar) called Vaikunth Dwar they reach Vaikunth as well! Temples all over the India makes a door kind of structure on this day for devotees to pass through that.

According to Padma Purana, the female energy of Lord Vishnu slains demon Muran in the form of a damsel and protects `Devas'. Impressed by the act, Lord Vishnu names her as `Ekadashi' and gives her the boon that those who worship `Ekadashi' on the day of her victory over Muran would reach `Vaikunth' (His abode).

In Mahabarata, Bhagavad Gita - the conversation between Lord Krishna and Arjuna at the beginning of Kurukshetra War is said to have occurred on this day.
People should indulge in meditation, Japa and singing of Hari Kirtan. Rice is avoided during ekadashi days as it is believed that the demon Mura finds a dwelling in the rice eaten on Ekadasi day.
Vaikunta Ekadashi is the Ekadashi that occurs in the Hindu calendar month of Margh Margashira (corresponding to late December - January in English calendar.)
This year Vaikuntha Ekadasi is on 7 January 2009.