JSFiddle - React, Tailwind, and code Playground
HTML
<table id="caltbl">
<thead>
<tr>
<th>
</th>
<th>
Date
</th>
<th>
hours
</th>
<th>
Module
</th>
<th>
..
</th>
</tr>
</thead>
<tbody>
<tr><td class="sortnr">759</td></tr>
<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>
</tbody>
</table>
JavaScript
var $tbody = $('#caltbl tbody');
$tbody.find('tr').sort(function (a, b) {
var tda = $(a).find('td:eq(0)').text();
var tdb = $(b).find('td:eq(0)').text();
// if a < b return 1
return tda > tdb ? 1
// else if a > b return -1
: tda < tdb ? -1
// else they are equal - return 0
: 0;
}).appendTo($tbody);