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Digital Clock using JavaScript

Neha Soni
Software Engineering Intern at FICO | Technical Blogger
Updated on ・5 min read

Hello readers,

In this article, you will learn how to design a simple animated Digital Clock in JavaScript. A digital clock or watch in which the hours, minutes, and sometimes seconds are indicated by digits, as opposed to an analog clock, where the time is indicated by the positions of rotating hands.

Let's get started

Prerequisite

  • Basic knowledge of HTML
  • Basic knowledge of CSS
  • Basic knowledge of JavaScript

It's Time to Code!

To create a digital clock first, you need to create three files one HTML File(index.html), the second one is CSS file(style.css) and the third one is JS file(index.js).

HTML code

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>Digital Clock</title>
    <link rel="stylesheet" href="style.css">
  </head>
    <body>
        <!--Display day information e.g Wednesday March 12,2021-->
        <div id="dayIntro">
            <p id="dayName"></p>
        </div>
        <div class="container">
            <!-- Display time -->
            <div class="dispClock">
                <div id="time"></div>
            </div>
        </div>
        <script src="index.js"></script>
    </body>
</html>
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CSS Code

style.css

/* Google font */
@import url('https://fonts.googleapis.com/css?family=Orbitron');

*{
    margin: 0;
    padding: 0;

  }
  html,body{
    display: grid;
    place-items: center;

  }
  #dayIntro
{
    font-size: 40px;
    font-weight: 600;
    letter-spacing: 3px;
    border: 7px solid rgb(17,129,134);
    border-radius: 10px;
    margin: 20px;
    font-family: 'Times New Roman', Times, serif;
    padding: 15px;
    background: linear-gradient(180deg, #a8b9d3,rgb(173, 227, 229));
}
  .container{
    height: 120px;
    width: 550px;
    position: relative;
    background: linear-gradient(135deg, #14ffe9, #ffeb3b, #ff00e0);
    border-radius: 10px;
    cursor: default;

  }
  .container .dispClock,
  .container {
    position: absolute;
    top: 28%;
    left: 50%;
    transform: translate(-50%, -50%);
  }
  .container .dispClock{
    top: 50%;
    height: 105px;
    width: 535px;
    background: linear-gradient(147deg, #000000 0%, #2c3e50 74%);
    border-radius: 6px;
    text-align: center;
  }
  .dispClock #time{
    line-height: 85px;
    color: #fff;
    font-size: 70px;
    font-weight: 600;
    letter-spacing: 1px;
    font-family: 'Orbitron', sans-serif;
    background: linear-gradient(135deg, #14ffe9, #ffeb3b, #ff00e0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;

  }
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JavaScript Code

Now here comes the main part. The entire code for the working of the clock is written within the currentTime() function.

Let's discuss everything step by step:-

Step 1:- Create a function currentTime().

function currentTime()
{
  //code to be executed
}
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Step 2:- Inside the function, create an object of Date Class which allows you to call day, year, month, day, hour, minute, second, etc.

function currentTime()
{
    const clock = document.getElementById("time")
    const dayIntro=document.getElementById("dayName");

    let time = new Date();        // creating object of Date class
    let dayName=time.getDay();
    let month=time.getMonth();
    let year=time.getFullYear();
    let date=time.getDate();
    let hour = time.getHours();
    let min = time.getMinutes();
    let sec = time.getSeconds();
}
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Step 3:- The Date object works on the 24-hour format so we change the hour back to 1 when it gets larger than 12. The AM/PM also changes according to that.

var am_pm = "AM";
   if(hour==12)
   am_pm = "PM";

   if (hour > 12) 
   {
     hour -= 12;
     am_pm = "PM";
   }
   if (hour == 0) 
   {
     hour = 12;
     am_pm = "AM";
   }
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Step 4:- The obtained hours, minutes, and seconds from Date object will be displayed in single-digit if less than 10. To display the elements of time in two-digit format, a 0 is appended before them whenever they are less than 10.

 hour = hour < 10 ? "0" + hour : hour;
 min = min < 10 ? "0" + min : min;
 sec = sec < 10 ? "0" + sec : sec;
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Step 5:- Now once our time is ready, make a string using the same HH: MM: SS format changing the hour, minute, and a second value with the values, we get from Date object methods.

//value of current time
let currentTime = hour + ":" + min + ":" + sec +" "+ am_pm;

// value of present day(Day, Month, Year)
var months=["January","February","March","April","May","June","July","August","September","October","November","December"];
var week=["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];

var presentDay=week[dayName]+", "+months[month]+" "+date+", "+year;
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Step 6:- Once the string is ready, let's display it in the div which we made before. This is done by obtaining the div using the document.getElementById method and give our time as the content of the div using the innerHTML property.

const clock = document.getElementById("time");
const dayIntro=document.getElementById("dayName");

clock.innerHTML = currentTime;
dayIntro.innerHTML = presentDay;
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Step 7:- To call the function every second use setInterval() method and set the time-interval as 1000ms which is equal to 1s.(Call setInterval() method outside the function).

setInterval(currentTime, 1000);
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Step 8:- Call the function currentTime() at the end to start function at exact reloading of page.

currentTime();  //calling currentTime() function to initiate the process 
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Complete javascript code

index.js

setInterval(currentTime, 1000);

function currentTime()
{
    let time = new Date();   // creating object of Date class
    let dayName=time.getDay();
    let month=time.getMonth();
    let year=time.getFullYear();
    let date=time.getDate();
    let hour = time.getHours();
    let min = time.getMinutes();
    let sec = time.getSeconds();

    var am_pm = "AM";
    if(hour==12)
    am_pm = "PM";
    if (hour > 12) {
    hour -= 12;
    am_pm = "PM";
    }
    if (hour == 0) {
    hour = 12;
    am_pm = "AM";
    }

    hour = hour < 10 ? "0" + hour : hour;
    min = min < 10 ? "0" + min : min;
    sec = sec < 10 ? "0" + sec : sec;

   //value of current time
   let currentTime = hour + ":" + min + ":" + sec +" "+ am_pm;

  // value of present day(Day, Month, Year)
  var months=["January","February","March","April","May","June","July","August","September","October","November","December"];
  var week=["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];

  var presentDay=week[dayName]+", "+months[month]+" "+date+", "+year;

  const clock = document.getElementById("time");
  const dayIntro=document.getElementById("dayName");

  clock.innerHTML = currentTime;
  dayIntro.innerHTML = presentDay;
}

currentTime();  //calling currentTime() function to initiate the process 
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congrats.gif
You have just created a digital clock. It will look something like this!.
Demo

If you enjoyed learning and find it useful please do like and share so that, it reaches others as well 🤝

Thanks for reading 😃

I would ❤ to connect with you at Twitter | LinkedIn | GitHub

Let me know in the comment section if you have any doubt or feedback.

You should definitely check out my other Blogs:

See you in my next Blog article, Take care!!

Happy Learning😃😃

Discussion (13)

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lukeshiru profile image
LUKE知る • Edited

Date has some methods to get the current date and time that are quite better than getting one by one. I recently found a similar post and added some suggestions there that would be pretty much the same for this one. Sharing if you're interested:

dev.to/lukeshiru/comment/1eaca

In short: You don't need to calculate AM/PM, and you can use template strings to make this simpler.

Cheers!

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nehasoni__ profile image
Neha Soni Author

Thanks for sharing the link. I’ll check it out!😊🤝

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inhuofficial profile image
InHuOfficial

Quick heads up, in your example (demo) the AM and PM can get pushed down onto the following line if the numbers are all wide numbers. Just needs a tiny bit of extra space adding to the container.

Other than that, looks great, very psychedelic! ❤️

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nehasoni__ profile image
Neha Soni Author

Don't worry I will check it and update the code 😊🤝

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kiranrajvjd profile image
Kiran Raj R

You can add "javascript" after your opening backticks for syntax highlighting.

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nehasoni__ profile image
Neha Soni Author

Woww... Thank you very much for this!
This really is awesome😍😍

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kiranrajvjd profile image
Kiran Raj R

Happy that the tip was useful

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itzmeelvis profile image
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nehasoni__ profile image
Neha Soni Author

Thank you🤝

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leandroruel profile image
Leandro RR

really cool article. i'm teaching my friend to code, she already learned the basics of html and css and some js. i'm going to give this challenge to her

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nehasoni__ profile image
Neha Soni Author

Thank you 😊😊
I hope your friend also find it useful🙌

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bubblicious profile image
bubblicious-a

great work

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nehasoni__ profile image
Neha Soni Author

Thank you😊🙌

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