YUI module for calculating the time ago in words in English. Updated from the Prototype version and optimized for compressor.

date-ago.js

YUI.add('date-ago', function (Y) {

  function round(value) {
    return Math.round(value);
  }
  
  function distanceOfTimeInWords(from_time, to_time, include_s) {
    var include_seconds, distance_in_minutes, distance_in_seconds;
    include_seconds = include_s || false;
    distance_in_minutes = round(Math.abs(to_time - from_time) / 60000);
    distance_in_seconds = round(Math.abs(to_time - from_time) / 1000);
    if (distance_in_minutes < 2) {
      if (include_seconds) {
        if (distance_in_seconds < 5) { return 'less than 5 seconds'; }
        if (distance_in_seconds < 10) { return 'less than 10 seconds'; }
        if (distance_in_seconds < 20) { return 'less than 20 seconds'; }
        if (distance_in_seconds < 40) { return 'half a minute'; }
        if (distance_in_seconds < 59) { return 'almost a minute'; }
        return '1 minute';
      }
      return (distance_in_minutes === 0) ? 'less than a minute' : '1 minute';
    }
    if (distance_in_minutes < 45) { return distance_in_minutes + ' minutes'; }
    if (distance_in_minutes < 89) { return '1 hour'; }
    if (distance_in_minutes < 1439) { return '' + round(distance_in_minutes / 60) + ' hours'; }
    if (distance_in_minutes < 2879) { return '1 day'; }
    if (distance_in_minutes < 43199) { return round(distance_in_minutes / 1440) + ' days'; }
    if (distance_in_minutes < 86399) { return '1 month'; }
    if (distance_in_minutes < 525599) { return round(distance_in_minutes / 43200) + ' months'; }
    if (distance_in_minutes < 1051199) { return '1 year'; }
    return 'over ' + round(distance_in_minutes / 525600) + ' years';
  }
  
  function timeAgoInWords(date, includeSeconds) {
    var now = new Date(),
        direction = (now - date > 0) ? ' ago' : ' from now';
    return distanceOfTimeInWords(date, now, includeSeconds) + direction;
  }
  
  Y.Date = Y.merge(Y.namespace('Date'), {
    // JS version of Ruby on Rails' distance_of_time_in_words
    distanceOfTimeInWords: distanceOfTimeInWords,
    // Returns the time since a date in English
    timeAgoInWords: timeAgoInWords
  });
  
}, "3.3.0");