JSFiddle - React, Tailwind, and code Playground

HTML

<div id="link_area" class="timed_links night">
    <a href="#" class="day">Link 1</a>
    <a href="#" class="day">Link 2</a>
    <a href="#" class="day">Link 3</a>
    <a href="#" class="night">Link 4</a>
    <a href="#" class="day night">Link 5</a>
</div>

CSS

.timed_links.day a.night,
.timed_links.night a.day
{
    display: none;
}

.timed_links.day a.day,
.timed_links.night a.night
{
    display: initial;
}

JavaScript

var hour = new Date().getHours();
if (hour < 23 || hour > 08) { // it's "day" time
    $('.timed_links').removeClass('night').addClass('day');
}
else { // it's "night" time
    $('.timed_links').removeClass('day').addClass('night');
}