proper syntax for cached dates

cached_dates.js

function localizable_time_ago_in_words(from, locale){
  "use strict"; 
  return distance_of_time_in_words(new Date(), new Date(from));
}

function distance_of_time_in_words(to, from) {
  "use strict"; 
  var seconds_ago = ((to - from) / 1000);
  var minutes_ago = Math.floor(seconds_ago / 60);
  /*!<sl:translate>*/
  if(minutes_ago <= 0) { return "less than a minute ago";}
  if(minutes_ago === 1) { return "a minute ago";}
  if(minutes_ago < 45) { return "{0} minutes ago".format(minutes_ago);}
  if(minutes_ago < 90) { return "1 hour ago";}
  var hours_ago = Math.round(minutes_ago / 60);
  if(minutes_ago < 1440) { return "{0} hours ago".format(hours_ago);}
  if(minutes_ago < 2880) { return "1 day ago";}
  var days_ago = Math.round(minutes_ago / 1440);
  if(minutes_ago < 43200) { return "{0} days ago".format(days_ago);}
  if(minutes_ago < 86400) { return "1 month ago";}
  var months_ago = Math.round(minutes_ago / 43200);
  if(minutes_ago < 525960) { return "{0} months ago".format(months_ago);}
  if(minutes_ago < 1051920) { return "1 year ago";}
  var years_ago = Math.round(minutes_ago / 525960);
  return "over {0} years ago".format(years_ago);
  /*!</sl:translate>*/
}

if(typeof jQuery !== 'undefined') {
  (function($) {
    "use strict"; 
    function convert_to_relative_date(element){
      var timestamp = $(element).attr('timestamp');
      var locale    = $(element).attr('locale');
      $(element).html( 
        localizable_time_ago_in_words(parseInt(timestamp, 10), locale) 
      );
    }

    function convert_all_dates_to_relative_date(){
      $('.i18n-date').each(function(){
        convert_to_relative_date(this);
      });
    }

    // apply quen document loads
    $(document).ready(function(){
      convert_all_dates_to_relative_date();

      //apply whenever ajaxy stuff happens
      $(document).ajaxComplete(function(){
        convert_all_dates_to_relative_date();
      });
    });

  })(jQuery);
}