JavaScript Canvas Countdown Timer

The JavaScript code snippet helps you to create a Canvas based Countdown Timer on a webpage. It uses an HTML canvas element to create a visual representation of the remaining days, hours, minutes, and seconds until a specified date. This timer is helpful for tracking time intervals or creating a sense of urgency on your website.

You can use this code on your website to add a stylish countdown timer. It’s beneficial for creating a sense of urgency, such as for limited-time promotions or event countdowns.

How to Create a Javascript Canvas Countdown Timer

1. First of all, load the Reset CSS by adding the following CDN link into the head tag of your HTML document.

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/meyer-reset/2.0/reset.min.css">

2. Create the HTML structure for your countdown timer. You can place it anywhere on your webpage. The code provides four canvas elements for days, hours, minutes, and seconds.

<div class="item-time">
  <div class="card">
    <div class="word">DAYS</div>
    <canvas class="days" width="50" height="50"></canvas>
  </div>
  <div class="card">
    <div class="word">HOUR</div>
    <canvas class="hours" width="50" height="50"></canvas>
  </div>
  <div class="card">
    <div class="word">MIN</div>
    <canvas class="minutes" width="50" height="50"></canvas>
  </div>
  <div class="card">
    <div class="word">SEC</div>
    <canvas class="seconds" width="50" height="50"></canvas>
  </div>
</div>

3. Add styles to your countdown timer using CSS. Customize the appearance to match your website’s design. The following CSS code helps you get started with a dark-themed countdown timer.

body{
 font-family: "Helvetica Neue", "Helvetica", Helvetica, Arial, sans-serif;
  background: #141414;
  display: flex;
  justify-content: center;
}
.item-time {
  display: grid;
  margin-top: 2rem;
  grid-template-columns: repeat(4, 1fr);
  column-gap: .5rem;
}
.word {
  text-align: center;
  font-size: 0.8rem;
  text-shadow: 0 1px 2px #000;
  color: #c1c1c1;
}
.card {
  background: #333;
  color: #ccc;
  padding: 0.5rem;
  border-radius: 0.4rem;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.7);
}

4. Finally, add the following JavaScript code to your project. It divides this time into days, hours, minutes, and seconds, and updates the canvas elements accordingly.

class Countdown {

    /**
     * @param {Date} dateTo
     */
    constructor(itemSelector, dateTo) {
        this.itemSelector = itemSelector;
        let $ = el => document.querySelector(el);
        this.dateSelectors = {
            d: $('.days').getContext('2d'),
            h: $('.hours').getContext('2d'),
            m: $('.minutes').getContext('2d'),
            s: $('.seconds').getContext('2d')
        };
        this.dateTo = dateTo;
        requestAnimationFrame(() => this.set());
    }

    /**
     * Main function
     */
    set() {

        let today = new Date();

        for (let selector in this.dateSelectors) {
            let s = this.dateSelectors[selector];
            this.clear(s);
            this.setTime(s, this.dateDiff(selector, today, this.dateTo));
        }
        requestAnimationFrame(() => this.set());
    }

    /**
     * Clear canvas
     * @param {canvas} ctx 
     */
    clear(ctx) { ctx.clearRect(0, 0, 60, 60); }

    setTime(ctx, until) {
        ctx.font = 'bold 2rem sans-serif';
        ctx.shadowColor = "#000";
        ctx.shadowOffsetX = 0;
        ctx.shadowOffsetY = 1;
        ctx.shadowBlur = 2;
        ctx.fillStyle = "#ccc";
        ctx.textAlign = "center";
        ctx.fillText(until, 25, 40);
    }

    /**
     * 
     * @param {String} datepart  enum {'m',  'd', 'h', 's'}
     * @param {Date} fromdate 
     * @param {Date} todate 
     */
    dateDiff(datepart, fromdate, todate) {
        datepart = datepart.toLowerCase();
        let diff = todate - fromdate;
        let divideBy = {
            d: 86400000,
            h: 3600000,
            m: 60000,
            s: 1000,
            ms: 1
        };

        let modulo = {
            d: 1,
            h: divideBy['d'],
            m: divideBy['h'],
            s: divideBy['m'],
            ms: divideBy['s']
        }

        return Math.floor(diff % modulo[datepart] / divideBy[datepart]);
    }

}

//set tomorrow date
new Countdown('.item-time', new Date(new Date().getTime() + 24 * 60 * 60 * 1000));

That’s all! hopefully, you have successfully created the JavaScript Canvas Countdown Timer on your website. If you have any questions or suggestions, feel free to comment below.

Asif Mughal

I code and create web elements for amazing people around the world. I like work with new people. New people new Experiences.
I truly enjoy what I’m doing, which makes me more passionate about web development and coding. I am always ready to do challenging tasks whether it is about creating a custom CMS from scratch or customizing an existing system.