From 656715da3458fbff7e261fe74c46a4ae61a8ca9e Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 28 Mar 2025 15:15:45 -0700 Subject: [PROPOSED 1/2] Give URLs for POSIX.1-2024 * theory.html: Add URL for POSIX.1-2024 (problem reported by Max Nikulin). Also add a URL for POSIX.1-1988 and make POSIX versions clearer. --- theory.html | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/theory.html b/theory.html index 352a3d87..96d1244a 100644 --- a/theory.html +++ b/theory.html @@ -89,15 +89,16 @@ The tz code is upwards compatible with POSIX, an international standard for UNIX-like systems. -As of this writing, the current edition of POSIX is POSIX.1-2024, -which has been published but not yet in HTML form. -Unlike its predecessor POSIX.1-2017 ( The Open -Group Base Specifications Issue 7, IEEE Std 1003.1-2017, 2018 -Edition), POSIX.1-2024 requires support for the +As of this writing, the current edition of POSIX is +POSIX.1-2024 +(The Open Group Base Specifications Issue 8, IEEE Std 1003.1-2024). +Unlike its predecessors +POSIX.1-1988 through +POSIX.1-2017, +POSIX.1-2024 requires support for the tz database, which has a model for describing civil time that is more complex than the -standard and daylight saving times required by POSIX.1-2017. +standard and daylight saving times required by earlier POSIX editions. A tz timezone corresponds to a ruleset that can have more than two changes per year, these changes need not merely flip back and forth between two alternatives, and the rules themselves @@ -914,7 +915,8 @@ environment variable TZ, which can have two forms:

POSIX.1-2017 properties and limitations

-Some platforms support only the features required by POSIX.1-2017, +Some platforms support only the features required by POSIX.1-2017 +and earlier editions, and have not yet upgraded to POSIX.1-2024. Code intended to be portable to these platforms must deal with problems that were fixed in later POSIX editions. -- 2.45.2