3v4l.org

run code in 300+ PHP versions simultaneously
<?php var_dump( date("o/W",strtotime("Sunday -8 days")), date("o/W",strtotime("Sunday -7 days")) );
Output for 5.6.0 - 5.6.29, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.5 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.28, 8.4.1 - 8.4.15, 8.5.0 - 8.5.1
string(7) "2016/52" string(7) "2016/52"
preferences:
156.02 ms | 408 KiB | 5 Q