On a watch, the countdown function is essentially the function of a reverse timer. You set a time limitation and count back down to zero. It is perfect for athletes, cooks who need an exact time, and even a meeting organizer. A countdown timer typically alerts a wearer before time is up, sometimes by an audible beep and sometimes by a visual signal for counting down, aids people in managing time-sensitive activities such as sports and diving watches. Besides being practical, a countdown function also adds utility value to a watch, particularly to one using precise timing all day.