Add WorkDays ( monday to friday ) to any moment

addWorkdays.js

const moment = require('moment');

moment.fn.addWorkdays = function (days) {
    // Getting negative / positive increment
    var increment = days / Math.abs(days);
    // Looping weeks for each full 5 workdays
    var date = this.clone().add(Math.floor(Math.abs(days) / 5) * 7 * increment, 'days');
    // Account for starting on Saturdays and Sundays
    if (date.isoWeekday() === 6) { date.add(-increment, 'days'); }
    else if (date.isoWeekday() === 7) { date.add(-2 * increment, 'days'); }
    // Adding / removing remaining days in a short loop, jumping over weekends
    var remaining = days % 5;
    while (remaining != 0) {
        date.add(increment, 'days');
        if (date.isoWeekday() !== 6 && date.isoWeekday() !== 7)
            remaining -= increment;
    }
    return date;
};