<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script src="https://unpkg.com/gijgo@1.9.13/js/gijgo.min.js" type="text/javascript"></script>
<link href="https://unpkg.com/gijgo@1.9.13/css/gijgo.min.css" rel="stylesheet" type="text/css" />
<input id="datepicker" width="276" />
<script>
$('#datepicker').datepicker({
uiLibrary: 'bootstrap4',
format: 'dd-mm-yyyy'
});
</script>