jquery datepicker - disable weekends and specific dates

jquery datepicker - disable weekends and specific dates

I've been trying to follow similar posts and the solutions do not seem to work for me.  Any help would be appreciated.  I'm trying to disable weekends and specific dates.  I can't seem to get the beforeShowDay working.  In the example below I can get either the weekends or the specific dates disabled by calling either onDate: $.datepick.noWeekends or onDate:nationalDays (respectively)

I'm using jQuery 1.4.4
Datepicker extensions for jQuery v4.0.5


var natDays = [[4, 15],[4, 28] ];
$(function() {
    $('#popupDatepicker').datepick();
    $('#inlineDatepicker').datepick({
        rangeSelect: true,
        monthsToShow: 2,
        minDate: +1, maxDate: +30,
        //onDate: $.datepick.noWeekends,
        //onDate:nationalDays,
        beforeShowDay:noWeekendsOrHolidays
    });
});



function nationalDays(date, inMonth) {
    if (inMonth) {
        for (i = 0; i < natDays.length; i++) {
            if (date.getMonth() + 1 == natDays[i][0] &&
                    date.getDate() == natDays[i][1]) {
                return [0, "disabled"];
            }
        }
    }
    return {};
}

function noWeekendsOrHolidays(date) {
  var noWeekend = $.datepick.noWeekends(date);
  if (noWeekend[0]) {
                        return nationalDays(date);
                } else {
                        return noWeekend;
                }

}