What is the least amount of time it takes for the bob to swing from a position of maximum displacement to the?

A large, simple pendulum is on display in the lobby of the United Nations building. If the pendulum is 18.7 m in length, what is the least amount of time it takes for the bob to swing from a position of maximum displacement to the equilibrium position of the pendulum? (ume that the acceleration of gravity is g = 9.81 m/s2 at the UN building.)