Only allow Monday, Tuesday or Wednesday in Shopware Datepicker

jquery.datepicker.js

$.overridePlugin('swDatePicker', {
    initFlatpickr: function () {
        var me = this;

        me.opts.disable = [
            function (date) {
                return (date.getDay() > 3 || date.getDay() === 0);
            }
        ];

        me.superclass.initFlatpickr.apply(this, arguments);
    }
});