#datepicker Odd behavior in different browsers

<link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css">
<link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/smoothness/jquery-ui.css">
<link rel="stylesheet" href="/resources/demos/style.css">

$(function () { $("#datepicker").datepicker(); $("#anim").on("change", function () { $("#datepicker").datepicker("option", "showAnim", $(this).val()); }); });

When this is rendered in chrome the datepicker looks as specified in Jquery reference. When it is rendered in Edge I get this odd calendar picker..... Works OK but my question is why are they rendered differently in the 2 browsers?