3v4l.org

run code in 300+ PHP versions simultaneously
<?php $yr="2011"; $week="01"; $day="Monday"; $day=date("D",strtotime($day)); $newdate= date("d-m-Y", strtotime($yr."W".$week."D ".$day));; echo $newdate; $k = explode("-", $newdate); $ymd = $k[2]."-".$k[1]."-".$k[1]; echo $ymd ?>
Output for 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 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 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
04-01-20112011-01-01
Output for 5.1.0 - 5.1.6
02-01-20112011-01-01
Output for 5.0.0 - 5.0.5
19-12-20102010-12-12
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9
01-01-19701970-01-01
preferences:
287.05 ms | 402 KiB | 372 Q