Bug #55686 [Com]: DateTime object getting stuck on Feb 29th

Edit report at https://bugs.php.net/bug.php?id=55686&edit=1 ID: 55686 Comment by: john at gbd dot co dot uk Reported by: salathe@php.net Summary: DateTime object getting stuck on Feb 29th Status: Assigned Type: Bug Package: Date/time related PHP Version: trunk-SVN-2011-09-13 (SVN) Assigned To: derick Block user comment: N Private report: N New Comment: Is this important? Pre-Julian dates were different, Feb had 23 or 24 days rather than the current 28/29 days, so any date pre 45BC is a bit academic. and probably beyond the scope of a PHP date function. http://en.wikipedia.org/wiki/Julian_calendar Previous Comments: ------------------------------------------------------------------------ [2011-09-13 20:52:21] salathe@php.net Description: ------------ Some dates falling on February 29th in negative years can not have an interval of one day added to them. The pattern appears to be years of the form -n16, but some years behave as expected (e.g. -816 and -416 in the test script below). Test script: --------------- <?php for ($i = -1000; $i < 1000; $i++) { $date = new DateTime('midnight', new DateTimeZone('UTC')); $date->setDate($i, 2, 29); // Rolled over into March, no Feb 29th, skip if ($date->format('M') !== 'Feb') { continue; } $next = clone $date; $next->add(new DateInterval('P1D')); if ($date->format('Y-m-d') === $next->format('Y-m-d')) { echo $next->format('Y-m-d l') . PHP_EOL; } } ?> Expected result: ---------------- No output is expected. Actual result: -------------- -0916-02-29 Friday -0716-02-29 Tuesday -0616-02-29 Sunday -0516-02-29 Friday -0316-02-29 Tuesday -0216-02-29 Sunday -0116-02-29 Friday ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=55686&edit=1