Dutch holidays

<?php

function is_dutch_public_holiday($date)
{
	$holidayDays = array();
	$date = date_i18n('Ymd', strtotime($date));
	$year = date_i18n('Y', strtotime($date));

	$nieuwjaar = new DateTime($year . "-01-01");
	$koningsdag = new DateTime($year . "-04-27");
	$kerstdag = new DateTime($year . "-12-25");
	$tweedeKerstdag = new DateTime($year . "-12-26");

	$paasdag = new DateTime(null, wpse198435_get_blog_timezone());
	$paasdag->setTimestamp(easter_date($year));

	$tweedePaasdag = clone $paasdag;
	$tweedePaasdag->add(new \DateInterVal('P1D')); // 1 dag na pasen
	$hemelvaart = clone $paasdag;
	$hemelvaart->add(new \DateInterVal('P39D')); // 39 dagen na pasen
	$pinksteren = clone $hemelvaart;
	$pinksteren->add(new \DateInterVal('P10D')); // 10 dagen na hemelvaart
	$tweedePinksterdag = clone $pinksteren;
	$tweedePinksterdag->add(new \DateInterVal('P1D')); // 1 dag na pinksteren

	$holidayDays[] = $nieuwjaar->format('Ymd');
	$holidayDays[] = $paasdag->format('Ymd');
	$holidayDays[] = $tweedePaasdag->format('Ymd');
	$holidayDays[] = $koningsdag->format('Ymd');
	$holidayDays[] = $hemelvaart->format('Ymd');
	$holidayDays[] = $pinksteren->format('Ymd');
	$holidayDays[] = $tweedePinksterdag->format('Ymd');
	$holidayDays[] = $kerstdag->format('Ymd');
	$holidayDays[] = $tweedeKerstdag->format('Ymd');

	if (in_array($date, $holidayDays)) {
		return true;
	}
	return false;
}