How to show weekends in calendar?

Question

I have installed fmstarting point solution and it has a calendar done by java.

How can I change default weekends from sat sun to other days?

The code is down below.

BR Dino

// This is where you can change the settings for your calendar.

var calendarEl = document.getElementById('calendar');
    var calendar;
    var initCalendar = function() {
        calendar = new FullCalendar.Calendar(calendarEl, {

            //Custom Button to add task
            customButtons: {
                FMNewTask: {
                    text: '+ Add Appointmen',
                        click: 
                        function() { 
                        var focus       = calendar.getDate().toISOString();
                        doThis      = NewTask(focus, '(0882)NewTask');
                        }
                    } 
            },
            plugins: [ 'interaction', 'dayGrid', 'timeGrid', 'list' ],
            height: 'parent',

            header: {
                left: 'FMAdd,FMNewTask',
                center: 'title',
                right:  'prev,next today'       //More options: 'dayGridMonth,timeGridWeek,timeGridDay,listWeek'
            },
            defaultView: '**VIEW**',
            defaultDate: '**DefaultDate**',
            navLinks: true,                 //Can click day/week names to navigate views.
            editable: true,
            eventLimit: true,               //Allow "more" link when too many events
            locale: 'en',                   //To change the locale. Examples: en-gb, fr, zh-tw
            slotDuration: '00:30:00',
            slotLabelInterval: '00:60:00',
            minTime: '10:00:00',
            maxTime: '19:00:00',
            scrollTime: '06:00:00',
            nowIndicator:true,
            weekends:true, 
            businessHours: false,
        businessHours: { daysOfWeek: [6,0,1,2,3,], // enable all days
startTime: '10:00',
endTime: '19:00',
},