Doc #76378 [Opn]: strftime format "%p" is not always uppercase "AM/PM"

Edit report at https://bugs.php.net/bug.php?id=76378&edit=1 ID: 76378 Updated by: requinix@php.net Reported by: webmaster at deltik dot org Summary: strftime format "%p" is not always uppercase "AM/PM" Status: Open Type: Documentation Problem Package: Date/time related Operating System: CloudLinux 7.5 and Ubuntu 18.04 PHP Version: Irrelevant Block user comment: N Private report: N New Comment: Also https://linux.die.net/man/3/strftime > %P > Like %p but in lowercase: "am" or "pm" or a corresponding string for the > current locale. (GNU) It's quite reasonable to assume from this that %p is uppercase. The fact is that PHP can't guarantee much when it comes to strftime. Only document what systems tend to do. So if %p tends to be uppercase AM/PM then the docs should say that, and if that's not always the case then the docs should say that too. Previous Comments: ------------------------------------------------------------------------ [2018-05-25 18:15:14] webmaster at deltik dot org Regardless of the locale or operating system, the PHP documentation has the wrong description of the "%p" conversion specification because it assumes that the format will be uppercase. ------------ DOCUMENTATION WITHOUT UPPERCASE ASSUMPTION ------------ https://msdn.microsoft.com/en-us/library/fe06s4ak.aspx > Current locale's A.M./P.M. indicator for 12-hour clock http://www.cplusplus.com/reference/ctime/strftime/ > AM or PM designation https://www.freebsd.org/cgi/man.cgi?query=strftime > is replaced by national representation of either "ante meridiem" (a.m.) or > "post meridiem" (p.m.) as appropriate. https://linux.die.net/man/3/strftime > Either "AM" or "PM" according to the given time value, or the > corresponding strings for the current locale. Noon is treated as "PM" and midnight as > "AM". ------------ DOCUMENTATION WITH UPPERCASE ASSUMPTION ------------ https://secure.php.net/manual/en/function.strftime.php > UPPER-CASE 'AM' or 'PM' based on the given time ------------------------------------------------------------------------ [2018-05-25 17:54:42] requinix@php.net PHP's strftime is a wrapper around the OS's strftime. I think it would be worth expanding the "Not all conversion specifiers..." paragraph (or adding a new one) to mention that while it's fairly well standardized, the exact behavior and output is system-dependent, "see your man page for strftime(3) or >>MSDN", something like that. After some searching, it seems the docs for 'nix derivatives say "AM/PM" while BSD's is more broad. So as far as I can tell, if you get "am/pm" in Ubuntu then that is contrary to its own strftime(3) docs which say it's either "AM" or "PM". Which means the locale is wrong, not PHP or the system. ------------------------------------------------------------------------ [2018-05-25 16:17:22] webmaster at deltik dot org Description: ------------ When the LC_TIME locale is set to "en_GB.UTF-8", the "%p" conversion specification returns lowercase "am" or "pm" instead of the documented "AM" or "PM". PHP documentation: https://secure.php.net/manual/en/function.strftime.php The documentation for the "%p" conversion specification reads: > UPPER-CASE 'AM' or 'PM' based on the given time In man 3 strftime, the description reads: > Either "AM" or "PM" according to the given time value, or the corresponding > strings for the current locale. Noon is treated as "PM" and midnight as "AM". The "en_GB.UTF-8" locale always expresses "am" and "pm" as lowercase, which makes the PHP documentation inaccurate. Sources: - https://sourceware.org/bugzilla/show_bug.cgi?id=3768 - https://en.wikipedia.org/wiki/Date_and_time_notation_in_the_United_Kingdom The documentation should be updated to explain that "%p" is "AM" or "PM" in the current locale, not necessarily uppercase, and that "%P" is the same as "%p" except lowercase. --------------- This bug was discovered in a unit test of a PHP application: https://github.com/e107inc/e107-test/pull/5#issuecomment-391903312 --------------- The "Expected result" below is what we should see if the PHP documentation were to be trusted. The "Actual result" is correct according to the actual strftime function. Test script: --------------- <?php echo setlocale(LC_TIME, "en_GB.UTF-8") . PHP_EOL . strftime("%I:%M %p", "1517834703") . PHP_EOL; echo PHP_EOL; echo setlocale(LC_TIME, "C") . PHP_EOL . strftime("%I:%M %p", "1517834703") . PHP_EOL; Expected result: ---------------- en_GB.UTF-8 12:45 PM C 12:45 PM Actual result: -------------- en_GB.UTF-8 12:45 pm C 12:45 PM ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=76378&edit=1