JSFiddle - React, Tailwind, and code Playground
HTML
<span class="mytime">8:18</span>
JavaScript
$(function () {
var timeElements = $('.mytime').text().split(":");
var theHour = parseInt(timeElements[0]);
var theMintute = timeElements[1];
var newHour = theHour + 24;
$('.mytime').text(newHour + ":" + theMintute);
});