3v4l.org

run code in 300+ PHP versions simultaneously
<?php $year = 2015; $period = new DatePeriod( new DateTime($year.'-01-01'), new DateInterval('P1M'), new DateTime(($year+1).'-01-01') ); foreach($period as $date){ $firstDay = $date->modify('first day of this month')->format("Y/m/d") ; $lastDay = $date->modify('last day of this month')->format("Y/m/d") ; echo "$firstDay - $lastDay \n"; }
Output for 5.6.0 - 5.6.24, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 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
2015/01/01 - 2015/01/31 2015/02/01 - 2015/02/28 2015/03/01 - 2015/03/31 2015/04/01 - 2015/04/30 2015/05/01 - 2015/05/31 2015/06/01 - 2015/06/30 2015/07/01 - 2015/07/31 2015/08/01 - 2015/08/31 2015/09/01 - 2015/09/30 2015/10/01 - 2015/10/31 2015/11/01 - 2015/11/30 2015/12/01 - 2015/12/31

preferences:
296.51 ms | 404 KiB | 182 Q