To run a piece of code after a certain time, you can use setTimeout function in JavaScript. It accepts a function and a time interval in milliseconds. It returns a unique id which you can use to clear the timeout using clearTimeout function.

const timeoutId = setTimeout(() => {
  console.log('Hello World');
}, 1000);
 
// Output:
// Hello World

In the above code, the setTimeout function runs the callback function after 1000 milliseconds (1 second) and prints Hello World to the console. It returns a unique id which you can use to clear the timeout using clearTimeout function.

clearTimeout(timeoutId);