Vaikunta Ekadashi is the Shukla Paksha Ekadashi that occurs during the Dhanu month in the Hindu calendar (corresponding to late December - January in English calendar).
The Vaishnava (Worship of Vishnu) sect believes that ‘Vaikunta Dwaram’ or ‘the gate to the Lord's Inner Sanctum’ is opened on this day. The Margashirsha Shukla Paksha Ekadashi in the Lunar calendar is known as a 'Mokshada Ekadashi.' Special prayers, yagnas, discourses and speeches are arranged at Vishnu temples across the world on this auspicious day. The Shaiva sect observes the day as Trikoti Ekadashi, a religious observance where all the deities in the Hindu pantheon pay obeisance to Lord Sri Shiva at once