Get number of business days in a selected month with Moment.js

getNumberOfBusinessDaysInMonth.js

// Usage: getNumberOfBusinessDaysInMonth(moment(), moment().daysInMonth());
function getNumberOfBusinessDaysInMonth(date, days) {
    var date = moment(date).startOf('month');
    var numberOfBusinessDays = 0;

    while (days > 0) {
        date = date.add(1, 'days');
        if (date.isoWeekday() !== 7 && date.isoWeekday() !== 1) {
            numberOfBusinessDays += 1;
        }
        days -= 1;
    }

    return numberOfBusinessDays;
}