3v4l.org

run code in 300+ PHP versions simultaneously
<?php $thirtyOnedayMonths = array( 1, 3, 5, 7, 8, 10, 12 ); $format = 'Y-m-d'; foreach($thirtyOnedayMonths as $month){ $date = date($format, strtotime('-1 month', strtotime("2013-{$month}-31 00:00:01"))); var_dump($date); }
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
string(10) "2012-12-31" string(10) "2013-03-03" string(10) "2013-05-01" string(10) "2013-07-01" string(10) "2013-07-31" string(10) "2013-10-01" string(10) "2013-12-01"
preferences:
254.59 ms | 406 KiB | 456 Q