function getElapsedWorkDays(a, b) {
  var days = b.diff(a, 'days');
  var start = a.day();
  var count = 0;
  for (var i = 0; i < days; i++) {
    start++;
    if (start > 6)
      start = 0;
    if (start > 0 && start < 6)
      count++;
  }
  return count;
}