- print_r: documentation ( source)
<?php
$today = new DateTime();
$rangeStart = new DateTime(((int) $today->format('Y') - 3) . '-01-01 00:00:00');
$rangeEnd = new DateTime(((int) $today->format('Y') + 10) . '-12-31 23:59:59');
$datePeriod = new DatePeriod($rangeStart, new DateInterval('P6M'), $rangeEnd);
print_r($datePeriod);