Bug #76731 [Opn->Nab]: Date time format parsing is wrong for format Ynd

Edit report at https://bugs.php.net/bug.php?id=76731&edit=1 ID: 76731 Updated by: requinix@php.net Reported by: remy dot fox at simbuka dot com Summary: Date time format parsing is wrong for format Ynd -Status: Open +Status: Not a bug Type: Bug Package: Date/time related PHP Version: 7.2.8 Block user comment: N Private report: N New Comment: Yeah, and the documentation for strftime says the two-digit day is %d. You have to look at the pages for the functions you're *actually using*. http://php.net/manual/en/datetime.createfromformat.php > d and j Day of the month, 2 digits with or without leading zeros 01 to 31 or 1 to > 31 > m and n Numeric representation of a month, with or without leading zeros 01 through 12 or 1 > through 12 Anyway, it sounds like you're satisfied with the current behavior given what 'm' and 'd' represent. Previous Comments: ------------------------------------------------------------------------ [2018-08-13 10:41:25] remy dot fox at simbuka dot com You are right that I made a mistake in the first example. On the date webpage (http://php.net/manual/en/function.date.php) the 'd' specifier is prescribed as 'Day of the month, 2 digits with leading zeros', which is why my conclusion was that the parsing must be wrong. Of course if the documentation is inaccurate because the 'd' actually means *up to* 2 digits, then the bug report is not valid. Though in my opinion *up to* 2 digits is rather confusing and I think that the current documentation on the date function (although not representing the current state of the functionality) is more consistent. I'd suggest fixing the functionality to match the date function's documentation rather than the other way around. ------------------------------------------------------------------------ [2018-08-13 07:58:57] derick@php.net Your first sample fails because you didn't specify the - in your format: derick@singlemalt:~ $ php <?php $date = DateTime::createFromFormat("Y-m-d", "2000-10-1"); var_dump($date); Standard input code:3: class DateTime#1 (3) { public $date => string(26) "2000-10-01 07:55:25.000000" public $timezone_type => int(3) public $timezone => string(3) "UTC" } Works just fine here. The format characters in createFromFormat take *up* to the amount of characters acceptable for the format. So indeed, the "Y" parses 4 characters ("2000"), the "m" parses 2 characters ("10"), and the "d" up to 2 characters, but as there is only one, it parses only "1". ------------------------------------------------------------------------ [2018-08-13 00:58:02] requinix@php.net > Both the month and day specifier are padded in 'Ymd' Optionally padded. 2000101 gets parsed as Y=2000 m=10 d=1 so the zero isn't being reused. PHP takes whatever digits are available when deciding whether to use one or two digits. If there are two digits available then they both will be used. That's why "200012" does not work with Ymd: Y=2000, m=12 because there are two digits available, and since there's nothing left for d to match it fails. Even though it could have matched with m=1 d=2. ------------------------------------------------------------------------ [2018-08-12 23:24:05] a at b dot c dot de Incidentally, I just noticed that this behaviour is documented on the createFromFormat() page. "d and j Day of the month, 2 digits with or without leading zeros" ------------------------------------------------------------------------ [2018-08-12 23:19:16] a at b dot c dot de In short: createFromFormat("Ymd", "2000101") should be rejected because it doesn't have enough digits, right? There should be four for the year, two for the month, and two for the day. The test case can be simplified: $date = DateTime::createFromFormat("d", "1"); var_dump($date); Of the other "leading zero" format specifiers, "m", "h" and "H" also parse, but "i" and "s" both fail. ------------------------------------------------------------------------ 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=76731 -- Edit this bug report at https://bugs.php.net/bug.php?id=76731&edit=1