old_contents: import moment from 'moment';
  import containedPeriodicValues from 'contained-periodic-values';
  
  moment.fn.weekDays = function(start) {
    var startDay = start.day();
    var totalDays = Math.abs(this.diff(start, 'days'));
  
    // Calculate the nearest Saturday and Sunday to our start day
    var containedSundays = containedPeriodicValues(startDay, totalDays + startDay, 0, 7);
    var containedSaturdays = containedPeriodicValues(startDay, totalDays + startDay, 6, 7);
  
    return totalDays - (containedSaturdays + containedSundays);
  };
  
  moment.fn.weekendDays = function(start) {
    // Total days - week days
    return Math.abs(this.diff(start, 'days')) - this.weekDays(start);
  };
  
new_contents: import moment from 'moment';
  import containedPeriodicValues from 'contained-periodic-values';
  
  moment.fn.weekDays = function(start) {
    var startDay = start.day();
    var totalDays = Math.abs(this.diff(start, 'days'));
  
    var containedSundays = containedPeriodicValues(startDay, totalDays + startDay, 0, 7);
    var containedSaturdays = containedPeriodicValues(startDay, totalDays + startDay, 6, 7);
  
    return totalDays - (containedSaturdays + containedSundays);
  };
  
  moment.fn.weekendDays = function(start) {
    // Total days - week days
    return Math.abs(this.diff(start, 'days')) - this.weekDays(start);
  };
  
subject: Update comment in src