3v4l.org

run code in 300+ PHP versions simultaneously
<?php $hour = date('H'); $foo = mktime($hour); var_dump(date('r', $foo), $hour, $foo);
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.38, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33, 8.0.0 - 8.0.12, 8.0.14 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
string(31) "Fri, 16 Oct 2015 19:46:31 +0200" string(2) "19" int(1445017591)
Output for 7.3.32 - 7.3.33, 8.0.13
string(31) "Fri, 16 Oct 2015 17:46:31 +0000" string(2) "17" int(1445017591)

preferences:
243.63 ms | 401 KiB | 366 Q