Exempt blocked dates on Jscript calendar

I'm using a Jscript calendar on a florist website.

They don't deliver on Sundays so that day is blocked out. However, they do deliver on one sunday -  Mothers day, 10/3/13.

Is there a way to make this one sunday date selectable?

$(function() {
$('#itemname6').datepicker({dateFormat: 'dd/mm/yy', minDate: 1, beforeShowDay: nonWorkingDates});
                                                
     setMinDate(); // Set it now
      setInterval(setMinDate, 60000); // And check every minute
});

//Now


function noSundays(date) {
      return [date.getDay() != 0, ''];
}



function nonWorkingDates(date) {
      
      var closedDates = [[1, 04, 2013], [06, 05, 2013], [27, 05, 2013], [26, 08, 2013], [25, 12, 2013], [26, 12, 2013]],
           day = date.getDay();
           for (var i = 0; i < closedDates.length; i++) {
            if (date.getDate() == closedDates[i][0] && date.getMonth() + 1 == closedDates[i][1] &&
                        date.getFullYear() == closedDates[i][2]) {

                  return [false, '']; // Closed date
            }
      }
      return [day > 0, '']; // Open if not Sunday
}
                                            

Select allOpen in new window