note 114826 added to class.dateinterval

invert flag is unreliable. If you've created interval with \DateInterval::createFromDateString with value like '1 day ago' than actually days counter will be negative, and invert flag will be 0. Also, setting invert to 1 with negative units is not working. Reliable solution to check if interval is negative is to actually apply it and compare: <?php private function isNegative(\DateInterval $interval) { $now = new \DateTimeImmutable(); $newTime = $now->add($interval); return $newTime < $now; } ?> Also, if you want to compare some units of two intervals you should take abs() of them. Or make whole interval absolute: <?php private function absInterval(\DateInterval $interval) { $now = new \DateTimeImmutable(); $new = $now->add($interval); $newInt = $now->diff($new); if (1 === $newInt->invert) { $newInt->invert = 0; } return $newInt; } ?> P.S.: tested on 5.5.12-dev and 5.5.9 ---- Server IP: 72.52.91.14 Probable Submitter: 109.188.125.156 ---- Manual Page -- http://php.net/manual/en/class.dateinterval.php Edit -- https://master.php.net/note/edit/114826 Del: integrated -- https://master.php.net/note/delete/114826/integrated Del: useless -- https://master.php.net/note/delete/114826/useless Del: bad code -- https://master.php.net/note/delete/114826/bad+code Del: spam -- https://master.php.net/note/delete/114826/spam Del: non-english -- https://master.php.net/note/delete/114826/non-english Del: in docs -- https://master.php.net/note/delete/114826/in+docs Del: other reasons-- https://master.php.net/note/delete/114826 Reject -- https://master.php.net/note/reject/114826 Search -- https://master.php.net/manage/user-notes.php