Buddhists believe that there have been innumerable time cycles (kalpas) of creation and destruction of the universe in the past, and there will be innumerable more in the future. These extremely long periods of time are known as eons. The buddha of the past eon was Dipamkara, the buddha of our current era is Shakyamuni, and the buddha of the future eon will be Maitreya. These three are often represented and worshiped together.