Check this example. Now please take its reference and correct your code.
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
</head>
<body>
    <input type="text" id="txtDate" readonly="readonly" />
    <script type="text/javascript" src="https://code.jquery.com/jquery-1.12.4.js"></script>
    <script type="text/javascript" src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
    <link rel="Stylesheet" type="text/css" href="https://code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css" />
    <style type="text/css">
        .myweekend span.ui-state-default {
            color: red;
        }
    </style>
    <script type="text/javascript">
        $(function () {
            $("#txtDate").datepicker({
                dateFormat: 'yy/mm/dd',
                changeMonth: true,
                changeYear: true,
                showButtonPanel: true,
                beforeShowDay: function (date) {
                    // Sets Weekend Friday and Saturday.
                    var weekend = date.getDay() == 5 || date.getDay() == 6;
                    return [!weekend, 'myweekend'];
                },
                // Sets Weekend position.
                firstDay: 6,
                closeText: "إغلاق",
                prevText: "<السابق",
                nextText: "التالي>",
                currentText: "اليوم",
                monthNames: ["يناير", "فبراير", "مارس", "أبريل", "مايو", "يونيو", "يوليو", "أغسطس", "سبتمبر", "أكتوبر", "نوفمبر", "ديسمبر"],
                monthNamesShort: ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"],
                dayNames: ["الأحد", "الاثنين", "الثلاثاء", "الأربعاء", "الخميس", "الجمعة", "السبت"],
                dayNamesShort: ["أحد", "اثنين", "ثلاثاء", "أربعاء", "خميس", "جمعة", "سبت"],
                dayNamesMin: ["ح", "ن", "ث", "ر", "خ", "ج", "س"],
                weekHeader: "أسبوع",
                isRTL: false,
                showMonthAfterYear: false,
                yearSuffix: ""
            });
        });
    </script>
</body>
</html>