Pikaday date picker how to disable the first week?,

I have a question about pikaday im trying to disable the first week, for example right now its 6 October so you should be only allowed to click a date after 13 October. but i cant get it to work. Can someone please help me out ?

This is the code i have right now

    var picker = new Pikaday({
        disableDayFn: function(date){
            // Disable Sunday and Saturday
            return date.getDay() === 0 || date.getDay() === 6;
        },
        field: document.getElementById('fecha'),
        minDate: new Date()
    });

const numWeeks = 1;
const now = new Date();
now.setDate(now.getDate() + numWeeks * 7);