jquery-timeago/jquery.timeago.js

/*
 * Time Ago (for jQuery) version: 0.1 (07/18/2008)
 * @requires jQuery v1.2 or later
 *
 * Timeago is a jQuery plugin that makes it easy to support automatically
 * updating fuzzy timestamps (e.g. "4 minutes ago" or "about 1 day ago").
 *
 * For usage and examples, visit:
 * http://timeago.yarp.com/
 *
 * Licensed under the MIT:
 * http://www.opensource.org/licenses/mit-license.php
 *
 * Copyright (c) 2008, Ryan McGeary (ryanonjavascript -[at]- mcgeary [*dot*] org)
 */
(function($) {
  $.timeago = function(timestamp) {
    // TODO: should take a Date, ISO8601, or element[title=iso8601]
    // return words if date or iso8601; convert and return element if element
    alert("jQuery.timeago helper not implemented yet");
  };

  $.extend($.timeago, {
    settings: {
      refreshSeconds: 60
    },
    inWords: function(distanceMillis) {
      var seconds = distanceMillis / 1000;
      var minutes = seconds / 60;
      var hours = minutes / 60;
      var days = hours / 24;
      var years = days / 365;

      var words = seconds < 45 && "less than a minute" ||
        seconds < 90 && "about 1 minute" ||
        minutes < 45 && Math.round(minutes) + " minutes" ||
        minutes < 90 && "about 1 hour" ||
        hours < 24 && Math.round(hours) + " hours" ||
        hours < 48 && "about 1 day" ||
        days < 30 && Math.floor(days) + " days" ||
        days < 60 && "about 1 month" ||
        days < 365 && Math.floor(days / 30) + " months" ||
        years < 2 && "about 1 year" ||
        Math.floor(years) + " years";

      return words + " ago";
    },
    parse: function(iso8601) {
      var s = iso8601.replace(/^\s+/, '').replace(/\s+$/, '');
      s = s.replace(/-/,"/").replace(/-/,"/");
      s = s.replace(/T/," ").replace(/Z/," UTC");
      s = s.replace(/([\+-]\d\d)\:?(\d\d)/," $1$2"); // -04:00 -> -0400
      return new Date(s);
    }
  });

  $.fn.timeago = function() {
    var self = this;
    self.each(refresh);

    var $s = $.timeago.settings;
    if ($s.refreshSeconds > 0) {
      setInterval(function() { self.each(refresh); }, ($s.refreshSeconds * 1000));
    }
  };

  function refresh() {
    var date = $.timeago.parse(this.title);
    $(this).text($.timeago.inWords(distance(date)));
  }

  function distance(date) {
    return (new Date().getTime() - date.getTime());
  }
})(jQuery);