3v4l.org

run code in 200+ PHP versions simultaneously
<?php $formatter = new IntlDateFormatter( 'en_US', IntlDateFormatter::FULL, IntlDateFormatter::FULL, 'Europe/London', IntlDateFormatter::GREGORIAN, "Y-MM-dd" ); echo $formatter->format( new DateTime('2017-12-31 12:00:00', new DateTimeZone('Europe/London')) );
based on sCQVS
Output for 7.0.0 - 7.4.0
2018-12-31