jQuery Datepicker - Disable weekends / holidays and the next three working days combined

Question

Using this rather neat approach I can disable weekends and holidays from the datepicker.

However, I want to combine this with the disabling of the next three busines

Answer 1

My case was very close, but idea is that number of business days should be added to script. I replaced AddWeekDays() to AddBusinessDays() from Junto example. So when calculation minday it skip all non-business days.

    //holidays
    var natDays = [
      [1, 1, 'uk'],
      [12, 25, 'uk'],
      [12, 26, 'uk']
    ];

    var dateMin = new Date();
    var weekDays = AddBusinessDays(3);

    dateMin.setDate(dateMin.getDate() + weekDays);

    function AddBusinessDays(weekDaysToAdd) {
      var curdate = new Date();
      var realDaysToAdd = 0;
      while (weekDaysToAdd > 0){
        curdate.setDate(curdate.getDate()+1);
        realDaysToAdd++;
        //check if current day is business day
        if (noWeekendsOrHolidays(curdate)[0]) {
          weekDaysToAdd--;
        }
      }
      return realDaysToAdd;

    }

    function noWeekendsOrHolidays(date) {
        var noWeekend = $.datepicker.noWeekends(date);
        if (noWeekend[0]) {
            return nationalDays(date);
        } else {
            return noWeekend;
        }
    }
    function nationalDays(date) {
        for (i = 0; i < natDays.length; i++) {
            if (date.getMonth() == natDays[i][0] - 1 && date.getDate() == natDays[i][1]) {
                return [false, natDays[i][2] + '_day'];
            }
        }
        return [true, ''];
    }


    $('#datepicker').datepicker(
    {
        inline: true,
        beforeShowDay: noWeekendsOrHolidays,
        altField: '#txtCollectionDate',
        showOn: "both",
        dateFormat: "dd/mm/yy",
        firstDay: 1,
        changeFirstDay: false,
        minDate: dateMin
    });