JSFiddle - React, Tailwind, and code Playground
HTML
<select name="data" class="autotime" id="EventStartTimeMin">
<option value=""></option>
<option value="00">00</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="30">30</option>
<option value="40">40</option>
<option value="50">50</option>
</select>
JavaScript
$('#EventStartTimeMin').change(function() {
if($(this).val()===""){
console.log('empty');
}
});