countdown timer in javascript

How to Create a Countdown Clock with days, Hours, Minutes, and Seconds

by

In this blog post, I shared a simple Javascript code of Countdown Clock with day, Hours, Minutes, and Seconds. Which is often used for an offer or for a birthday countdown. So lets start

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Create a Countdown Clock</title>
    <link rel="stylesheet" href="style.css">
    

</head>
<body style="background-color: lightcyan;">

  <div class="container">
    <h1 id="headline">Countdown to end offer:</h1>
    <div id="countdown">
      <ul>
        <li><span id="days"></span>days</li>
        <li><span id="hours"></span>Hours</li>
        <li><span id="minutes"></span>Minutes</li>
        <li><span id="seconds"></span>Seconds</li>
      </ul>
    </div>
    <div id="content" class="emoji">
      <span>😔</span>
      <span>😢</span>
      <span>😔</span>
    </div>
  </div>
  
  
  <script src="script.js"></script>
</body>
</html>

script.js

(function () {
    const second = 1000,
          minute = second * 60,
          hour = minute * 60,
          day = hour * 24;
  
    let offer= "Sep 05, 2021 00:00:00",
        countDown = new Date(offer).getTime(),
        x = setInterval(function() {    
  
          let now = new Date().getTime(),
              distance = countDown - now;
  
          document.getElementById("days").innerText = Math.floor(distance / (day)),
            document.getElementById("hours").innerText = Math.floor((distance % (day)) / (hour)),
            document.getElementById("minutes").innerText = Math.floor((distance % (hour)) / (minute)),
            document.getElementById("seconds").innerText = Math.floor((distance % (minute)) / second);
  
          //do something later when date is reached
          if (distance < 0) {
            let headline = document.getElementById("headline"),
                countdown = document.getElementById("countdown"),
                content = document.getElementById("content");
  
            headline.innerText = "Ohhh no! Offer has ended";
            countdown.style.display = "none";
            content.style.display = "block";
  
            clearInterval(x);
          }
          //seconds
        }, 0)
    }());

You can change time in line number 7 let offer= “Sep 05, 2021 00:00:00”,

style.css

/* general styling */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
  
  html, body {
    height: 100%;
    margin: 0;
  }
  
  body {
    align-items: center;
    display: flex;
    font-family: -apple-system, 
      BlinkMacSystemFont, 
      "Segoe UI", 
      Roboto, 
      Oxygen-Sans, 
      Ubuntu, 
      Cantarell, 
      "Helvetica Neue", 
      sans-serif;
  }
  
  .container {
    color: #333;
    margin: 0 auto;
    text-align: center;
  }
  
  h1 {
    font-weight: normal;
    letter-spacing: .125rem;
    text-transform: uppercase;
  }
  
  li {
    display: inline-block;
    font-size: 1.5em;
    list-style-type: none;
    padding: 1em;
    text-transform: uppercase;
  }
  
  li span {
    display: block;
    font-size: 4.5rem;
  }
  
  .emoji {
    display: none;
    padding: 1rem;
  }
  
  .emoji span {
    font-size: 4rem;
    padding: 0 .5rem;
  }
  
  @media all and (max-width: 768px) {
    h1 {
      font-size: 1.5rem;
    }
    
    li {
      font-size: 1.125rem;
      padding: .75rem;
    }
    
    li span {
      font-size: 3.375rem;
    }
  }

After finish countdown