A kalpa is a long period of time (aeon) in Hindu and Buddhist cosmology, generally between the creation and recreation of a world or universe. Etymology Kalpa () in this context, means "a long period of time (aeon) related to the lifetime of the universe (creation)." It is derived from कॢप् (kḷp) +‎ -अ (-a, nominalizing suffix) (). Hinduism In Hinduism, a kalpa is equal to 4.32 billion years, a "day of Brahma" (12-hour day proper) or one thousand mahayugas, measuring the duration of the world. Each kalpa is divided into 14 manvantara periods, each lasting 71 Yuga Cycles (306,720,000 years). Preceding the first and following each manvantara period is a juncture (sandhya) equal to the length of a Satya Yuga (1,728,000 years). A kalpa is followed by a pralaya (dissolution) of equal length, which together constitute a day and night of Brahma. A month of Brahma contains thirty such days and nights, or 259.2 billion years. According to the Mahabharata, 12 months of Brahma (=360 days) constitute his year, and 100 such years his life called a maha-kalpa (311.04 trillion years or 36,000 kalpa + 36,000 pralaya). Fifty years of Brahma are supposed to have elapsed, and we are now in the Shveta-Varaha Kalpa or the first day of his fifty-first year. At the end of a kalpa, the world is annihilated by fire. The definition of a kalpa equaling 4.32 billion years is found in the Puranas—specifically Vishnu Purana and Bhagavata Purana. The Matsya Purana (290.3–12) lists the names of 30 kalpas, each named by Brahma based on a significant event in the kalpa and the most glorious person in the beginning of the kalpa. These 30 kalpas or days (along with 30 pralayas or nights) form a 30-day month of Brahma. The Vayu Purana has a different list of names for 33 kalpas, which G. V. Tagare describes as fanciful derivations. Buddhism In the Pali language of early Buddhism, the word kalpa takes the form kappa, and is mentioned in the assumed oldest scripture of Buddhism, the Sutta Nipata. This speaks of "Kappâtita: one who has gone beyond time, an Arahant". This part of the Buddhist manuscripts dates back to the middle part of the last millennium BCE. Gautama Buddha claimed an incalculable number of Buddhas lived in previous kalpas: Vipassi Buddha 91 kalpas ago, Sikhi Buddha 31 kalpas ago, and three prior Buddhas in the present