Req #53831 [Com]: DateInterval constructor does not handle valid ISO 8601 strings

Edit report at https://bugs.php.net/bug.php?id=53831&edit=1 ID: 53831 Comment by: pegasus at vaultwiki dot org Reported by: pallinger at dsd dot sztaki dot hu Summary: DateInterval constructor does not handle valid ISO 8601 strings Status: Not a bug Type: Feature/Change Request Package: Date/time related Operating System: ubuntu linux 10.10 PHP Version: 5.3.5 Assigned To: derick Block user comment: N Private report: N New Comment: According to the RFC cited as the reason for closing this report: "This information is based on the 1988 version of ISO 8601. There may be some changes in the 2000 revision." However, when discussing the basis for the accepted formats for DateInterval, the PHP documentation (https://www.php.net/manual/en/dateinterval.construct.php) links not to the cited RFC but to the Wikipedia page for ISO 8601, which reflects more recent versions of the ISO that were written after 1988. If PHP devs insist this is not a bug, then the documentation should be updated to point to the RFC, and not to a page that discusses features of the ISO that PHP has not implemented. Previous Comments: ------------------------------------------------------------------------ [2020-02-28 00:58:09] googleguy@php.net Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php Closing. This feature won't be implemented in php at the current time. ------------------------------------------------------------------------ [2020-02-27 19:12:44] googleguy@php.net This may be considered more of a feature request than a bug, however, I'm assigning to Derrick and pinging them here. When I looked at "Appendix A. ISO 8601 Collected ABNF" of RFC3339, I only see the definition of Seconds Duration as DIGIT, not fraction: Durations: dur-second = 1*DIGIT "S" dur-minute = 1*DIGIT "M" [dur-second] dur-hour = 1*DIGIT "H" [dur-minute] dur-time = "T" (dur-hour / dur-minute / dur-second) dur-day = 1*DIGIT "D" dur-week = 1*DIGIT "W" dur-month = 1*DIGIT "M" [dur-day] dur-year = 1*DIGIT "Y" [dur-month] dur-date = (dur-day / dur-month / dur-year) [dur-time] Additionally, section 5.3 of the RFC may seem to indicate that this not required by the specification: --- 5.3. Rarely Used Options A format which includes rarely used options is likely to cause interoperability problems. This is because rarely used options are less likely to be used in alpha or beta testing, so bugs in parsing are less likely to be discovered. Rarely used options should be made mandatory or omitted for the sake of interoperability whenever possible. The format defined below includes only one rarely used option: fractions of a second. It is expected that this will be used only by applications which require strict ordering of date/time stamps or which have an unusual precision requirement. --- However, I'll leave this to Derick to decide. It does seem to be a highly sought after feature and it would make sense to add it in the interval spec. Derick, any thoughts on this? ------------------------------------------------------------------------ [2019-01-10 19:15:05] mdwyer at michaelmdwyer dot com This appears to still be an issue with PHP 7.2, despite them adding a microseconds field to DateInterval. My current workaround is: $fractional = new DateInterval('PT0S'); $fractional->f = ".{$microseconds}"; $fractional->invert = $seconds < 0; return (new DateTime("@{$seconds}"))->add($fractional); ------------------------------------------------------------------------ [2017-12-05 22:46:04] sloanlance+php dot net at gmail dot com I'm surprised this bug has persisted since 2011-01-24. This seems to have been implemented incorrectly from the beginning. ISO 8601 has mentioned support for fractional parts since at least 2004. That is, it supports a decimal fraction to the smallest time value in a representation. For example, the following representations are valid ISO 8601 intervals, but will cause the DateInterval constructor to throw exceptions: P0.5Y P2.3D P1DT1.5H PT585.829S I appreciate the attempted workaround by "jdp2234 at hotmail dot com", but it appears to only support milliseconds. It doesn't seem to address fractions in other parts of interval representations. ------------------------------------------------------------------------ [2012-04-02 10:47:20] jdp2234 at hotmail dot com http://joshp.me/dateinterval-milliseconds/ Quick class to get around it, while the bug still exists... class DateIntervalFractions extends DateInterval { public $milliseconds; public function __construct($interval_spec) { $this->milliseconds = 0; $matches = array(); preg_match_all("#([0-9]*[.,]?[0-9]*) [S]#",$interval_spec,$matches); foreach ($matches[0] as $result) { $original = $result; list($seconds,$milliseconds) = explode(".",substr($result,0,-1)); $this->milliseconds = $milliseconds / pow(10,strlen($milliseconds) - 3); // Replace the milliseconds back to seconds, // and let the original constructor do the rest. $interval_spec = str_replace($original,$seconds . "S",$interval_spec); } parent::__construct($interval_spec); } } ------------------------------------------------------------------------ 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=53831 -- Edit this bug report at https://bugs.php.net/bug.php?id=53831&edit=1