You could use diffInDaysFiltered
to achieve what you're after.
Assuming your holidays are an array of Carbon
instances you could do something like:
$start = Carbon::now()->setDate(2014, 1, 1);
$end = Carbon::now()->setDate(2015, 1, 1);
$holidays = [
Carbon::create(2014, 2, 2),
Carbon::create(2014, 4, 17),
Carbon::create(2014, 5, 19),
Carbon::create(2014, 7, 3),
];
$days = $start->diffInDaysFiltered(function (Carbon $date) use ($holidays) {
return $date->isWeekday() && !in_array($date, $holidays);
}, $end);
If it's just an array of strings then you could do something like:
!in_array($date->format('[the-format-of-your-dates]'), $holidays)
Hope this helps!