The first accurate, modern clock was the pendulum clock. It was invented in 1656 by a Dutch scientist, Christian Huygens. When he first built the pendulum, it had an error of 1 minute per day.
Wristwatches were first officially invented in 1868 when a watch was created for the Countess of Hungary. Prior to the first official wristwatch, pocket watches were adapted to be worn on the wrist as early as 1570.