JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="night">
    <li>Foo</li>
    <li>Bar</li>
    <li>Baz</li>
</ul>

<ul id="day">
</ul>

JavaScript

var night = document.getElementById("night");
var day = document.getElementById("day");
var lis = document.querySelectorAll("#night > li");

for (var i = 0; i < lis.length; i++) {
    day.appendChild(lis[i]);
}