What is a Countdown Timer and its Purpose?

A countdown timer is a simple application that counts down the time until a specified event or duration ends. For example, it might start from “5 days 12 hours 30 minutes 20 seconds” and update every second down to “0 days 0 hours 0 minutes 0 seconds”.

Countdown timers are useful for tracking events (sales, launches, deadlines) and informing users how much time remains. In our project, the purpose is to let the user input a duration (days, hours, minutes, seconds), start the countdown, and see the time decrement live until it reaches zero. When the timer finishes, the app will display a final message (e.g. “Time’s up!”) to notify the user.

Aim of the project

The aim of this project is to build a functional, beginner-friendly React app for a countdown timer. We will start from scratch—installing Node.js, creating the React project, and writing all the code ourselves. The timer will allow input of days/hours/minutes/seconds, update every second, and show a message when done. We will also deploy the project to Netlify so the app is live online. By the end of the tutorial, you will learn React basics like components, state and effect hooks, and how to host a React app on Netlify.