3v4l.org

run code in 300+ PHP versions simultaneously
<?php echo date('d/m/Y'); print "\n"; echo date('d/m/Y', strtotime("1-W".date('W')."-".date('Y'))); print "\n"; echo date('d/m/Y', strtotime("2013-W01-1")); ?>
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 - 5.6.40, 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
05/01/2015 01/01/1970 31/12/2012
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.1.0 - 5.1.6
05/01/2015 01/01/1970 01/01/1970
Output for 5.0.0 - 5.0.5
05/01/2015 15/07/2006 31/12/2012
preferences:
291.79 ms | 401 KiB | 460 Q