Bug #76848 [Asn->Sus]: Possible to create Datetime from wrong month day

Edit report at https://bugs.php.net/bug.php?id=76848&edit=1 ID: 76848 Updated by: cmb@php.net Reported by: wojciech dot mocek at gmail dot com Summary: Possible to create Datetime from wrong month day -Status: Assigned +Status: Suspended Type: Bug Package: Date/time related Operating System: Linux PHP Version: 7.3.11 Assigned To: derick Block user comment: N Private report: N New Comment: Okay, apparently Java implements truncation, but PHP implements wrap-around (like date(1) does). It is debatable which solution is preferable, but since PHP implements wrap-around since "forever", and the behavior is documented[1], changing that would require the RFC process[2]. Feel free to start it. For the time being, I'm suspending this ticket. [1] <https://www.php.net/manual/en/datetime.examples-arithmetic.php#example-2506> [2] <https://wiki.php.net/rfc/howto> Previous Comments: ------------------------------------------------------------------------ [2020-03-18 17:29:46] fzty at pm dot me I encountered this issue on PHP 7.4.1 NTS x64. I tested a few more edge cases where an exception was expected but instead a DateTime object was created: # The zeroeth day of the month should not be accepted. var_dump(new DateTime('2020-01-00')); // "2019-12-31 00:00:00.000000" # The zeroeth month of the year should not be accepted. var_dump(new DateTime('2020-00-00')); // "2019-11-30 00:00:00.000000" # I'm not sure whether year 10000 should be accepted. var_dump(new DateTime('10000-01-01')); // "2000-01-01 10:00:00.000000" Like wojciech said, this is not representative of real life scenarios. The end result is that we have to write extra boilerplate validation to handle such edge cases. ------------------------------------------------------------------------ [2020-01-20 17:39:27] girgias@php.net Delegating this to Derick as he is the maintainer of the date extension. ------------------------------------------------------------------------ [2019-10-25 23:49:02] wojciech dot mocek at gmail dot com This bug occurs also on PHP 7.3.11. ------------------------------------------------------------------------ [2019-10-25 23:40:42] wojciech dot mocek at gmail dot com You asked "should both evaluate to the same value, shouldn't they?". So the answer is: no, they should not. This is how it was solved in other object language: $ docker container run --rm -it openjdk jshell Oct 25, 2019 11:21:53 PM java.util.prefs.FileSystemPreferences$1 run INFO: Created user preferences directory. | Welcome to JShell -- Version 13.0.1 | For an introduction type: /help intro jshell> var dateA = java.time.LocalDate.parse("2018-01-31"); jshell> dateA.plusMonths(1) $2 ==> 2018-02-28 jshell> var dateB = java.time.LocalDate.parse("2018-02-31"); | Exception java.time.format.DateTimeParseException: Text '2018-02-31' could not be parsed: Invalid date 'FEBRUARY 31' (...) Do you agree that PHP DateTime class is class for handling date and time? If yes, then do you agree that it should behave according to real date&time? If yes, then do we have in our calendar date '2018-02-31'? ------------------------------------------------------------------------ [2018-11-21 15:10:06] cmb@php.net Obviously, new DateTime('2018-01-31 +1 month') and new DateTime('2018-02-31') should both evaluate to the same value, shouldn't they? ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=76848 -- Edit this bug report at https://bugs.php.net/bug.php?id=76848&edit=1