Countdown Timer using HTML, CSS & JavaScript ⏰
In this video, I built a fully functional Countdown Timer using pure HTML, CSS, and JavaScript.
The focus of this project was handling date-based calculations, interval control, and dynamic UI updates. Unlike a simple stopwatch, a countdown timer requires computing the difference between the current time and a selected future date — and updating the UI every second accurately.
Features:
Select custom date and time
Start, Stop, and Reset controls
Live countdown display
Displays selected target date & time
Fully responsive UI
Tech Stack:
HTML – layout structure
CSS – minimal and responsive styling
JavaScript (ES6+) – time difference calculations and interval handling
Live - https://countdown-timer-navy-chi.verc...
Github - https://github.com/surajprojects/time...
What I focused on:
Calculating time differences correctly
Managing setInterval without duplication bugs
Handling edge cases (past dates, reset behavior)
Updating UI in real-time
Keeping logic modular and readable
This project is part of my build-in-public journey, where I share real-world projects and practical frontend logic as I grow toward full-stack development.
If you're strengthening your JavaScript fundamentals and learning how time-based logic works in real applications, this one’s for you.