https://www.hotelserenarieti.it/templates/template_5/js/jquery.datepick-en.js

1function convertiData(data, formato) {
2    formato = formato.replace("DD", (data.getDate() < 10 ? '0' : '') + data.getDate());
3    formato = formato.replace("MM", (data.getMonth() < 9 ? '0' : '') + (data.getMonth() + 1));
4    formato = formato.replace("YYYY", data.getFullYear());
5    return formato;
6}
7
8var currentDate = convertiData(new Date(), "DD/MM/YYYY");
9$("#date-input").val(currentDate);
10var oggi = moment(currentDate, 'DD/MM/YYYY');
11var headerHtml = $("#material-header-holder .ui-datepicker-material-header");
12
13var weekday = new Array(7);
14    weekday[1] = "Monday";
15    weekday[2] = "Tuesday";
16    weekday[3] = "Wednesday";
17    weekday[4] = "Thursday";
18    weekday[5] = "Friday";
19    weekday[6] = "Saturday";
20    weekday[7]=  "Sunday";
21
22$("#date-input").click(function(){
23    var getData = $("#date-input").val();
24    oggi = moment(getData, 'DD/MM/YYYY');
25    changeMaterialHeader(headerHtml, oggi);
26});
27
28var changeMaterialHeader = function(header, date) {
29    var year   = date.format('YYYY');
30    var month  = date.format('MMM');
31    var dayNum = date.format('D');
32    var isoDay = date.isoWeekday();
33    
34    $('.ui-datepicker-material-day', header).text(weekday[isoDay]);
35    $('.ui-datepicker-material-year', header).text(year);
36    $('.ui-datepicker-material-month', header).text(month);
37    $('.ui-datepicker-material-day-num', header).text(dayNum);
38    
39    $(".ui-datepicker").prepend(headerHtml);
40};
41
42$("input[data-type='date']").on("focus", function() {
43   $(".ui-datepicker").prepend(headerHtml);
44});
45
46$("input[data-type='date']").datepicker({
47  showButtonPanel: false,
48  autoSize: true,
49  dateFormat: "dd/mm/yy",
50  showAnim: "fadeIn",
51  firstDay: 1,
52  minDate: currentDate,
53  dayNamesMin: ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"],
54  monthNames: ['January','February','March','April','May','June','July','August','September','October','November','December'],
55  onSelect: function(date, inst) {
56    changeMaterialHeader(headerHtml, moment(date, 'DD/MM/YYYY'));
57  }
58});
59
60$('.ui-datepicker').addClass('notranslate');