Artur Le?niewski

I add this code in functions.php

add_action( 'wp_enqueue_scripts', 'load_theme_scripts' );

function load_theme_scripts() {
    global $wp_scripts; 
    $wp_scripts->registered[ 'wcj-datepicker' ]->src = get_template_directory_uri() . '/woocommerce-jetpack/includes/js/wcj-datepicker.js';
}

I’ve overwritten the file

/**
 * wcj-datepicker.
 *
 * @version 3.0.0
 * @todo    maybe_exclude_dates: <code>date.getDate()</code>, <code>date.getFullYear()</code>
 * @see     maybe_exclude_dates: https://stackoverflow.com/questions/501943/can-the-jquery-ui-datepicker-be-made-to-disable-saturdays-and-sundays-and-holid
 */

jQuery(document).ready(function() {  
	jQuery("input[display='date']").each( function () {
            
                 var datePickerInline = jQuery(this).parent().append('<div/>');
                 
                 
		var mindate = jQuery(this).attr("mindate");
		if (mindate === 'zero') {
			mindate = 0;
		}
		var maxdate = jQuery(this).attr("maxdate");
		if (maxdate === 'zero') {
			maxdate = 0;
		}
                
                jQuery(this).hide();
                
                datePickerInline.datepicker({
                    inline: true,
                    dateFormat : jQuery(this).attr("dateformat"),
                    minDate : mindate,
                    maxDate : maxdate,
                    firstDay : jQuery(this).attr("firstday"),
                    changeYear: jQuery(this).attr("changeyear"),
                    yearRange: jQuery(this).attr("yearrange"),
                    beforeShowDay: maybe_exclude_dates,
                    altField: '#'+jQuery(this).attr('id'),
                    dayNamesMin: ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"]
                });

                jQuery('#'+jQuery(this).attr('id')).change(function(){
                    datePickerInline.datepicker('setDate', $(this).val());
                });
                            
                
		function maybe_exclude_dates(date){
			var exclude_days = jQuery(this).attr("excludedays");
			if (typeof exclude_days !== typeof undefined && exclude_days !== false) {
				var day = date.getDay();
				for (var i = 0; i < exclude_days.length; i++) {
					if (day == exclude_days[i]) {
						return [false];
					}
				}
			}
			var exclude_months = jQuery(this).attr("excludemonths");
			if (typeof exclude_months !== typeof undefined && exclude_months !== false) {
				var month = date.getMonth() + 1;
				for (var i = 0; i < exclude_months.length; i++) {
					if (month == exclude_months[i]) {
						return [false];
					}
				}
			}
			return [true];
		}
	});
});