JSFiddle - React, Tailwind, and code Playground
HTML
<input id="start" class="datepicker" />
<input id="end" class="datepicker" />
<div></div>
JavaScript
$('.datepicker').datepicker();
$('.datepicker').change(function(){
if($('#start').val().length && $('#end').val().length){
$('div').append('<select id="combo" class="select" >'+
'<option>'+$('#start').val()+'</option>'+
'<option>'+$('#end').val()+'</option>');
}
});