3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $yr="2014"; $week="01"; $day="mon"; $day=date("D",strtotime($day)); echo date("Y-m-d", strtotime($yr."W".$week."D ".$day));; ?>
Output for 5.2.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
2014-01-03
Output for 5.1.0 - 5.1.6
2013-12-29
Output for 5.0.0 - 5.0.5
2013-12-22
Output for 4.3.0 - 4.4.9
1970-01-01