- printf: documentation ( source)
<?php
$onMay31 = DateTime::createFromFormat("F Y", "June 2017");
$bangDate = DateTime::createFromFormat("!F Y", "June 2017");
$pipeDate = DateTime::createFromFormat("F Y|", "June 2017");
printf("Regular date: %s\nBang date: %s\nPipe date: %s", $onMay31->format("M j, Y"), $bangDate->format("M j, Y"), $pipeDate->format("M j, Y"));