JSFiddle - React, Tailwind, and code Playground

HTML

<table id="caltbl">
    <thead>
        <tr>
            <th>
            </th>
            <th>
                Date
            </th>
            <th>
                hours
            </th>
            <th>
                Module
            </th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td class="sortnr">1</td>
            <td></td>
        </tr>
        <tr>
            <td class="sortnr">3</td>
            <td></td>
        </tr>
        <tr>
            <td class="sortnr">2</td>
            <td></td>
        </tr>
        <tr>
            <td class="sortnr">4</td>
            <td></td>
        </tr>
    </tbody>
</table>

JavaScript

var rows = $('#caltbl > tbody').children('tr').get();
rows.sort(function(a, b) {
    var anum = parseInt($(a).find(".sortnr").text(), 10);
    var bnum = parseInt($(b).find(".sortnr").text(), 10);
    return anum-bnum;
});
for (var i = 0; i < rows.length; i++) {
    $('#caltbl > tbody').append(rows[i]);
}