- var_dump: documentation ( source)
<?php
$locale = "de";
$intlTimezone = \IntlTimeZone::createDefault();
$dateTimezone = $intlTimezone->toDateTimeZone();
$calendar = new \IntlGregorianCalendar($intlTimezone, $locale);
$dateFormatter = \IntlDateFormatter::create($locale, 2, -1, $intlTimezone, $calendar, "dd.MM.y");
$time = DateTimeImmutable::createFromFormat("Y-m-d", "978-12-27", $dateTimezone);
var_dump($time);
var_dump($time->format("d.m.Y"));
var_dump($dateFormatter->format($time));