JSFiddle - React, Tailwind, and code Playground
HTML
<ul id="whatson">
<li> <span class="chkdate">06/01</span> somestuff2</li>
<li> <span class="chkdate">06/02</span> somestuff1</li>
<li> <span class="chkdate">06/03</span> somestuff2</li>
<li> <span class="chkdate">06/04</span> somestuff2</li>
<li> <span class="chkdate">06/05</span> somestuff2</li>
<li> <span class="chkdate">06/07</span> somestuff2</li>
<li> <span class="chkdate">06/20</span> somestuff2</li>
</ul>
JavaScript
var d = new Date();
d.setHours(0, 0, 0, 0);
var year = d.getFullYear();
$(".chkdate").each(function (i) {
((new Date($(this).text() + "/" + year)).setHours(0, 0, 0, 0) < d) ? $(this).closest("li").hide() : $(this).closest("li").show();
});