3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $yr="2011"; $week="01"; $day="Monday"; echo date("Y-m-d", strtotime($yr."W".$week."D ".$day));; echo date("D",strtotime($day)); ?>
Output for 5.2.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
2011-01-04Mon
Output for 5.1.0 - 5.1.6
2011-01-02Mon
Output for 5.0.0 - 5.0.5
2010-12-19Mon
Output for 4.3.0 - 4.4.9
1970-01-01Mon