JSFiddle - React, Tailwind, and code Playground

HTML

<span class="WorkingHours">
   M,W,Th,F 7:30 AM - 4:00 PM &lt;br /&gt;Tu 7:30 AM - 6:00 PM &lt;br /&gt;
</span>

JavaScript

var $content = $('<div />').html($('.WorkingHours').text());

$content.find('br').last().replaceWith('.').end().replaceWith(' ');

$('.WorkingHours').html($content.html());