JavaScript getMonth() returning 0 for the month of December. Why? [duplicate]

I don’t understand why the following code returns 0 as opposed to returning 11 (the index of the month of December).

function timeForMilkAndCookies(date) {
  return date.getMonth();
}

console.log(timeForMilkAndCookies(new Date(2025, 12, 3))); // returns 0