Pure JS - Display Time Elapsed & Remaining

What?
This is an example of Javascript code to update and display the elapsed/remaining hours minutes and seconds in real-time.

Why?
I know there are a lot of articles out there that write about the same, but this is an example that I was coding and found to be one of the most reduced cut down formats I've made. I thought I'd make a note of it to not have to search elsewhere...

This example specifically displays the time remaining on an access_token which is generated from an OAuth 2.0 process. I want to display to the user how much time is left before another access token will be generated and how long ago was the last token created.

How?
So almost pure JS. I'm working out the seconds remaining and seconds elapsed in PHP first then passing these as two variables to the below code but you could get your values from anywhere:
  1. On page load, the seconds remaining and elapsed are specified
  2. JS then takes over and runs the time
copyraw
var seconds_remaining = <?php echo ( filemtime($TOKEN_FILE)+3600 ) - time(); ?>;
var seconds_elapsed = <?php echo time() - filemtime($TOKEN_FILE); ?>;

setInterval('showTime()', 1000);

function showTime(){
    seconds_remaining--;
    seconds_elapsed++;
    if(seconds_remaining>=0){
        document.getElementById("time_remaining").innerHTML = returnTime( seconds_remaining );
        document.getElementById("time_ago").innerHTML = returnTime( seconds_elapsed );
    }
}

function returnTime( s ){
    hours = parseInt(s / 3600);
    s = (s % 3600);
    minutes = parseInt(s / 60);
    s = (s % 60);
    seconds = parseInt(s);
    str1 = ("0" + hours).slice(-2);
    str2 = ("0" + minutes).slice(-2);
    str3 = ("0" + seconds).slice(-2);
    return str1 + ':' + str2 + ':' + str3;
}
  1.  var seconds_remaining = <?php echo ( filemtime($TOKEN_FILE)+3600 ) - time(); ?>
  2.  var seconds_elapsed = <?php echo time() - filemtime($TOKEN_FILE); ?>
  3.   
  4.  setInterval('showTime()', 1000)
  5.   
  6.  function showTime(){ 
  7.      seconds_remaining--; 
  8.      seconds_elapsed++
  9.      if(seconds_remaining>=0){ 
  10.          document.getElementById("time_remaining").innerHTML = returnTime( seconds_remaining )
  11.          document.getElementById("time_ago").innerHTML = returnTime( seconds_elapsed )
  12.      } 
  13.  } 
  14.   
  15.  function returnTime( s ){ 
  16.      hours = parseInt(s / 3600)
  17.      s = (s % 3600)
  18.      minutes = parseInt(s / 60)
  19.      s = (s % 60)
  20.      seconds = parseInt(s)
  21.      str1 = ("0" + hours).slice(-2)
  22.      str2 = ("0" + minutes).slice(-2)
  23.      str3 = ("0" + seconds).slice(-2)
  24.      return str1 + ':' + str2 + ':' + str3; 
  25.  } 

The HTML would be something like:
copyraw
<table>
<tr><td>Time Remaining: </td><td id="time_remaining"></td></tr>
<tr><td>Time Elapsed: </td><td id="time_elapsed"></td></tr>
</table>
  1.  <table> 
  2.  <tr><td>Time Remaining: </td><td id="time_remaining"></td></tr> 
  3.  <tr><td>Time Elapsed: </td><td id="time_elapsed"></td></tr> 
  4.  </table> 
Category: JavaScript :: Article: 650

Credit where Credit is Due:


Feel free to copy, redistribute and share this information. All that we ask is that you attribute credit and possibly even a link back to this website as it really helps in our search engine rankings.

Disclaimer: Please note that the information provided on this website is intended for informational purposes only and does not represent a warranty. The opinions expressed are those of the author only. We recommend testing any solutions in a development environment before implementing them in production. The articles are based on our good faith efforts and were current at the time of writing, reflecting our practical experience in a commercial setting.

Thank you for visiting and, as always, we hope this website was of some use to you!

Kind Regards,

Joel Lipman
www.joellipman.com

Related Articles

Joes Revolver Map

Joes Word Cloud

Accreditation

Badge - Certified Zoho Creator Associate
Badge - Certified Zoho Creator Associate

Donate & Support

If you like my content, and would like to support this sharing site, feel free to donate using a method below:

Paypal:
Donate to Joel Lipman via PayPal

Bitcoin:
Donate to Joel Lipman with Bitcoin bc1qf6elrdxc968h0k673l2djc9wrpazhqtxw8qqp4

Ethereum:
Donate to Joel Lipman with Ethereum 0xb038962F3809b425D661EF5D22294Cf45E02FebF
© 2024 Joel Lipman .com. All Rights Reserved.