iso8601をDateオブジェクトに変換する ref: http://qiita.com/webbingstudio@github/items/74ff85bdac03f1a9aec7

iso8601date.js

var iso8601Date = function(iso) {
    var parse = iso.match(/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})\+\d{2}:\d{2}/);
    return new Date( Number(parse[1]), Number(parse[2]), Number(parse[3]), Number(parse[4]), Number(parse[5]), Number(parse[6]) );
};

...

var pubdate = iso8601Date( '2016-10-12T17:47:15+09:00' );

console.log(pubdate[1]); //2016