JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://trentrichardson.com/examples/timepicker/jquery-ui-timepicker-addon.js"></script>
<link rel="stylesheet" href="http://trentrichardson.com/examples/timepicker/jquery-ui-timepicker-addon.css">
<link rel="stylesheet" href="http://code.jquery.com/ui/1.9.2/themes/smoothness/jquery-ui.css">
<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.9/jquery.validate.js"></script>
<body>
    <form id="newuserjournal" name="newuserjournal" action="#" method="post">
        <input type="text" name="journalentrydate" id="journalentrydate" />
        <button type="submit" name="submit" id="submit">Save Date</button>
    </form>
</body>

CSS

.error {
    font: normal 10px arial;
    padding: 3px;
    margin: 3px;
    background-color: #ffc;
    border: 1px solid #c00;
}
body {
    font-size:x-large;
    background:#CCC;
}
h1 {
    margin-bottom:20px;
}
form {
    padding:50px;
}

JavaScript

$(document).ready(function () {
    jQuery.validator.addMethod(
        "dateTime",

    function (value, element, params) {
        if (!/Invalid|NaN/.test(new Date(value))) {
            return true;
        }

        return false;
    },
        'Must be in YYYY-MM-DD HH:mm format.');

    $("#newuserjournal").validate({
        debug: true,
        rules: {
            journalentrydate: {
                required: true,
                dateTime: true
            }
        },
        messages: {
            journalentrydate: {
                required: "Must have a date",
                dateTime: "Must be in YYYY-MM-DD HH:mm format"
            }
        }
    });

    $("#journalentrydate").datetimepicker({
        minDate: "-1Y",
        maxDate: 0,
        dateFormat: "yy-mm-dd",
        hideIfNoPrevNext: true,
        showButtonPanel: true,
        changeMonth: true,
        changeYear: true,
        selectOtherMonths: true,
        showOtherMonths: true,
        numberOfMonths: 1
    });
    $("#journalentrydate").datetimepicker("setDate", (new Date()));
});