I’m trying to use “createdCell” to sort the column, I want to create a dynamic “data-order” attribute…

I have this HTML:

<table id="datatable_promotions" class="table table-striped w-100">
                <thead>
                <tr>
                    <th>ID-BricoIO</th>
                    <th>ID-Volantino</th>
                    <th>Titolo</th>
                    <th>Codice</th>
                    <th>Data inizio</th>
                    <th>Data fine</th>
                    <th>Modifica</th>
                </tr>
                </thead>
                <tfoot>
                <tr>
                    <th>ID-BricoIO</th>
                    <th>ID-Volantino</th>
                    <th>Titolo</th>
                    <th>Codice</th>
                    <th>Data inizio</th>
                    <th>Data fine</th>
                    <th>Modifica</th>
                </tr>
                </tfoot>
</table>

And this JS:

datatable_promotions = $('#datatable_promotions').DataTable({
                paging: true,
                lengthMenu: [10, 25, 50, 75, 100],
                pageLength: 25,
                searching: true,
                order: [
                    [3, 'desc'],
                ],
                ordering: true,
                columns: [
                    {
                        visible: true,
                        orderable: true,
                        searchable: true,
                        type: 'string',
                        data: 'promo_id',
                        render: function (data, type, row) {
                            return data;
                        },
                    },
                    {
                        visible: true,
                        orderable: true,
                        searchable: true,
                        type: 'string',
                        data: 'id_volantino',
                        render: function (data, type, row) {
                            if (data === null) {
                                return '*****';
                            }
                            return data;
                        },
                    },
                    {
                        visible: true,
                        orderable: true,
                        searchable: true,
                        type: 'string',
                        data: 'title',
                        render: function (data, type, row) {
                            return data;
                        },
                    },
                    {
                        visible: true,
                        orderable: true,
                        searchable: true,
                        type: 'string',
                        data: 'code',
                        render: function (data, type, row) {
                            return data;
                        },
                    },
                    {
                        visible: true,
                        orderable: true,
                        searchable: false,
                        type: 'string',
                        data: 'date_start',
                        render: function (data, type, row) {
                            return row.date_start_formatted;
                        },
                        createdCell: function (cell, cellData, rowData, rowIndex, colIndex) {
                            $(cell).attr('data-order', rowData.date_start);
                            //$(cell).attr('data-sort', rowData.date_start);
                        },
                    },
                    {
                        visible: true,
                        orderable: true,
                        searchable: false,
                        type: 'string',
                        data: 'date_end',
                        render: function (data, type, row) {
                            return row.date_end_formatted;
                        },
                    },
                    {
                        visible: true,
                        orderable: false,
                        searchable: false,
                        type: 'string',
                        data: 'id',
                        render: function (data, type, row) {
                            return '<div class="text-center"><button class="btn btn-sm btn-primary fw-bold">Gestisci</button></div>';
                        },
                    },
                ],
            });

And I update the table with:

datatable_promotions.clear().rows.add(data).draw(false);

I’m interested in the fact that at render time, the text shown in a specific column is a date in d/m/Y format, while to maintain the ordering I would need data-order=”date(‘Y-m-d’)”.