codice HTML:
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="//code.jquery.com/ui/1.13.2/themes/base/jquery-ui.css">
    <title>Document</title>
</head>

<body>
    <form action="#" method="post">
        <input type="text" id="id_class_data_presunta_spedizione" value="">
    </form>

    <script src="https://code.jquery.com/jquery-3.6.0.js"></script>
    <script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
    <!-- <script src="https://code.jquery.com/ui/1.13.2/jquery-ui.js"></script> -->
    <script>

        $(document).ready(function () {
            /* Italian initialisation for the jQuery UI date picker plugin. */
            /* Written by Antonello Pasella (antonello.pasella@gmail.com). */
            (function (factory) {
                "use strict";

                if (typeof define === "function" && define.amd) {

                    // AMD. Register as an anonymous module.
                    define(["../widgets/datepicker"], factory);
                } else {

                    // Browser globals
                    factory(jQuery.datepicker);
                }
            })(function (datepicker) {
                "use strict";

                datepicker.regional.it = {
                    closeText: "Chiudi",
                    prevText: "Prec",
                    nextText: "Succ",
                    currentText: "Oggi",
                    monthNames: ["Gennaio", "Febbraio", "Marzo", "Aprile", "Maggio", "Giugno",
                        "Luglio", "Agosto", "Settembre", "Ottobre", "Novembre", "Dicembre"],
                    monthNamesShort: ["Gen", "Feb", "Mar", "Apr", "Mag", "Giu",
                        "Lug", "Ago", "Set", "Ott", "Nov", "Dic"],
                    dayNames: ["Domenica", "Lunedì", "Martedì", "Mercoledì", "Giovedì", "Venerdì", "Sabato"],
                    dayNamesShort: ["Dom", "Lun", "Mar", "Mer", "Gio", "Ven", "Sab"],
                    dayNamesMin: ["Do", "Lu", "Ma", "Me", "Gi", "Ve", "Sa"],
                    weekHeader: "Sm",
                    dateFormat: "dd/mm/yy",
                    firstDay: 1,
                    isRTL: false,
                    showMonthAfterYear: false,
                    yearSuffix: ""
                };
                datepicker.setDefaults(datepicker.regional.it);
                return datepicker.regional.it;
            });

            $(function () {
                $("#id_class_data_presunta_spedizione").datepicker({
                    changeMonth: true,
                    changeYear: true,
                    dateFormat: 'dd-mm-yy',
                    yearRange: "2010:2040"
                });
            });
        })

    </script>
</body>

</html>