<!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>Countdown numbers HTML CSS Js</title>
  
  <!-- Box icons CDN -->
	<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/boxicons@latest/css/boxicons.min.css">
  <link rel="stylesheet" href="https://unpkg.com/boxicons@latest/css/boxicons.min.css">
</head>
<body>
  <div class="wrapper">
    <div class="container">
      <i class='bx bxs-landscape'></i>
      <span class="num" data-val="400">000</span>
      <span class="text">Memories</span>
    </div>
  </div>
</body>
</html>
@import url('https://fonts.googleapis.com/css2?family=Merriweather:wght@900&family=Poppins&display=swap');

*
{
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

body
{
  height: 100vh;
  background-color: #121317;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* .wrapper
{
  border: 1px solid white;
  position: absolute;
  width: 80vw;
  transform: translate(-50%, -50%);
  top: 50%;
  left: 50%;
  display: flex;
} */

.container
{
/*   width: 28vmin;
  height: 28vmin; */
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  padding: 1em 2em;
  position: relative;
  font-size: 16px;
  border-radius: 0.5em;
  background-color: #21242b;
  border-bottom: 10px solid #18f98f;
}

i
{
  color: #18f98f;
  font-size: 2.8em;
  text-align: center;
}

span.num
{
  color: #ffffff;
  text-align: center;
  font-weight: 600;
  font-size: 3em;
  font-family: 'Merriweather', serif;
}

span.text
{
  color: #e0e0e0;
  text-align: center;
  font-weight: 400;
  font-family: 'Poppins', sans-serif;
}
let valueDisplays = document.querySelectorAll(".num");

let interval = 5000;

// console.log(valueDisplays);

valueDisplays.forEach((valueDisplay) => {
  let startValue = 0;
  let endValue = parseInt(valueDisplay.getAttribute("data-val"));
  
  // console.log(endValue);
  
  let duration = Math.floor(interval / endValue);
  
  let counter = setInterval(function(){
    startValue += 1;
    valueDisplay.textContent = startValue;
    
    if(startValue == endValue)
    {
      clearInterval(counter);
    }
  });
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.