In Hinduism, Kalki (meaning 'Eternity,' 'White Horse,' or 'Destroyer of Filth') is the final incarnation of Vishnu in the current kalpa, foretold to appear at the end of Kali Yuga, the current epoch. Religious texts called the Puranas foretell that Kalki will be atop a white horse with a drawn blazing sword. He is the harbinger of end time in Hindu eschatology, after which he will usher in Satya Yuga.
The name Kalki is a metaphor for eternity or time. Its origins may lie in the Sanskrit word kalka which means foulness or filth. Hence, the name translates to the 'destroyer of foulness,' 'destroyer of darkness," or 'destroyer of ignorance.' Another etymology from Sanskrit is 'white horse.'
In Buddhist Kalachakra tradition, 25 rulers of the Shambhala Kingdom held the title of Kalki, Kulika or Kalki-king. During Vaishakha, the first fortnight in Shukla Paksha is dedicated to fifteen deities, with each day for a different god. In this tradition, the twelfth day is Vaishakha Dwadashi and is dedicated to Madhava, another name for Kalki.