3v4l.org

run code in 300+ PHP versions simultaneously
<?php if (class_exists('DateTime')) { $date = new DateTime('2013-10-31'); $date->modify('-1 month'); print "2013-10-31, -1 month: {$date->format('m')}"; $date = new DateTime('2013-10-31'); $date->modify('first day of 1 month ago'); print "2013-10-31, first day of 1 month ago: {$date->format('m')}"; } else { print 'Not supported.'; }

preferences:
38.8 ms | 402 KiB | 5 Q