phpjs/experimental/datetime/date_interval_format.js

php.js offers community built php functions in javascript

function date_interval_format(dateIntervalObj) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: var dtIntvObj = date_interval_create_from_date_string('+1 day');
  // *     example 1: date_interval_format(dtIntvObj);
  // *     returns 1: '+1 day'

  // Fix need to check return to the example above

  return dateIntervalObj.format();
}