JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.17/themes/base/jquery-ui.css">
<input id="dt" /><input type="text" id="time" />

<input type="hidden" id="start" />

JavaScript

$("#dt").datepicker({
    onSelect: function(dateText, inst) {
        var date = $(this).val();
        var time = $('#time').val();
        alert('on select triggered');
        $("#start").val(date + time.toString(' HH:mm').toString());
        console.log(date + time.toString(' HH:mm').toString());
    }
});