highcharts - HighStock - The time displayed on UI is different from the server data -

it seems there error in demo of highstock demos › flags marking events

the chart display data 2013-06-02 2015-06-30

however, data fetched via ajax (http://www.highcharts.com/samples/data/jsonp.php?filename=usdeur.json&callback=?) shows time range [2013-05-02, 2015-05-30]

anybody know reason?