Eleventy-friendly "time ago" javascript snippet.

timeAgo.js

/**
* "Time Ago" vanilla javascript snippet
* 
* Lovingly stolen from StackOverflow here: https://stackoverflow.com/a/37802747
* 
* Convert elements like this:
*   <time datetime="Thu May 12 2022 21:05:56 GMT+0000 (Coordinated Universal Time)">May 12th, 2022</time>
*
* To This:
*   <time datetime="Thu May 12 2022 21:05:56 GMT+0000 (Coordinated Universal Time)">4 days ago</time>
* 
**/ 

var TimeAgo = (function() {
  var self = {};

  // Public Methods
  self.locales = {
    prefix: '',
    sufix:  'ago',

    seconds: 'less than a minute',
    minute:  'about a minute',
    minutes: '%d minutes',
    hour:    'about an hour',
    hours:   'about %d hours',
    day:     'a day',
    days:    '%d days',
    month:   'about a month',
    months:  '%d months',
    year:    'about a year',
    years:   '%d years'
  };

  self.inWords = function(timeAgo) {
    var seconds = Math.floor((new Date() - parseInt(timeAgo)) / 1000),
        separator = this.locales.separator || ' ',
        words = this.locales.prefix + separator,
        interval = 0,
        intervals = {
          year:   seconds / 31536000,
          month:  seconds / 2592000,
          day:    seconds / 86400,
          hour:   seconds / 3600,
          minute: seconds / 60
        };

    var distance = this.locales.seconds;

    for (var key in intervals) {
      interval = Math.floor(intervals[key]);

      if (interval > 1) {
        distance = this.locales[key + 's'];
        break;
      } else if (interval === 1) {
        distance = this.locales[key];
        break;
      }
    }

    distance = distance.replace(/%d/i, interval);
    words += distance + separator + this.locales.sufix;

    return words.trim();
  };

  return self;
}());


window.addEventListener('DOMContentLoaded', function (event) {
  // Get all elements with the class "time-ago"
  let timeAgoElements = document.getElementsByClassName('time-ago');

  // Loop through each timeago element
  for (let i = 0; i < timeAgoElements.length; i++) {
    let timeAgoElement = timeAgoElements[i];

    let time = new Date(timeAgoElement.getAttribute('datetime'));

    timeAgoElement.innerText = TimeAgo.inWords(time.getTime());
  }
});