Bug #71687 [NEW]: Adding one year to a leap day produces incorrect date

From: kungfutse at hotmail dot com Operating system: Linux PHP version: 5.6.18 Package: Date/time related Bug Type: Bug Bug description:Adding one year to a leap day produces incorrect date Description: ------------ When adding one year (new DateInterval('P1Y')) to a leap day (new DateTime('2016-02-29')) results in incorrect date. It should return 2017-02-28 but returns 2017-03-01 instead. For comparison, MariaDB 10 returns the correct date when doing SELECT DATE_ADD(DATE('2016-02-29'), INTERVAL 1 YEAR); Test script: --------------- var_dump( (new \DateTime('2016-02-29'))->add(new \DateInterval('P1Y')) ); Expected result: ---------------- object(DateTime)#1 (3) { ["date"]=> string(26) "2017-02-28 00:00:00.000000" ["timezone_type"]=> int(3) ["timezone"]=> string(15) "Europe/Helsinki" } Actual result: -------------- object(DateTime)#1 (3) { ["date"]=> string(26) "2017-03-01 00:00:00.000000" ["timezone_type"]=> int(3) ["timezone"]=> string(15) "Europe/Helsinki" } -- Edit bug report at https://bugs.php.net/bug.php?id=71687&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=71687&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=71687&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=71687&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=71687&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=71687&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=71687&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=71687&r=needscript Try newer version: https://bugs.php.net/fix.php?id=71687&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=71687&r=support Expected behavior: https://bugs.php.net/fix.php?id=71687&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=71687&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=71687&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=71687&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=71687&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=71687&r=dst IIS Stability: https://bugs.php.net/fix.php?id=71687&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=71687&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=71687&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=71687&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=71687&r=mysqlcfg