From b477cff35d3f5513e57f71a34272bebd1c205ed3 Mon Sep 17 00:00:00 2001 From: Eli Zaretskii Date: Sun, 2 Jan 2022 09:30:15 +0200 Subject: [PATCH] Clarify %g and %G time format specs * src/timefns.c (Fformat_time_string): * doc/lispref/os.texi (Time Parsing): Clarify %g/%G. (Bug#52934) --- doc/lispref/os.texi | 11 +++++++++-- src/timefns.c | 7 ++++--- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi index a08af898789..b1c19e384be 100644 --- a/doc/lispref/os.texi +++ b/doc/lispref/os.texi @@ -1793,9 +1793,16 @@ This stands for the ISO 8601 date format, which is like @samp{%+4Y-%m-%d} except that any flags or field width override the @samp{+} and (after subtracting 6) the @samp{4}. @item %g -This stands for the year corresponding to the ISO week within the century. +@cindex ISO week, in time formatting +This stands for the year without century (00--99) corresponding to the +current @dfn{ISO week} number. ISO weeks start on Monday and end on +Sunday. If an ISO week begins in one year and ends in another, the +rules regarding which year @samp{%g} will produce are complex and will +not be described here; however, in general, if most of the week's days +are in the ending year, @samp{%g} will produce that year. @item %G -This stands for the year corresponding to the ISO week. +This stands for the year with century corresponding to the current ISO +week number. @item %h This is a synonym for @samp{%b}. @item %H diff --git a/src/timefns.c b/src/timefns.c index 809ffafea4f..3e533ca51dc 100644 --- a/src/timefns.c +++ b/src/timefns.c @@ -1422,8 +1422,9 @@ without consideration for daylight saving time. The value is a copy of FORMAT-STRING, but with certain constructs replaced by text that describes the specified date and time in TIME: -%Y is the year, %y within the century, %C the century. -%G is the year corresponding to the ISO week, %g within the century. +%Y is the year, %y year without century, %C the century. +%G is the year corresponding to the ISO week, %g year corresponding + to the ISO week, without century. %m is the numeric month. %b and %h are the locale's abbreviated month name, %B the full name. (%h is not supported on MS-Windows.) @@ -1431,7 +1432,7 @@ by text that describes the specified date and time in TIME: %u is the numeric day of week from 1 (Monday) to 7, %w from 0 (Sunday) to 6. %a is the locale's abbreviated name of the day of week, %A the full name. %U is the week number starting on Sunday, %W starting on Monday, - %V according to ISO 8601. + %V the week number according to ISO 8601. %j is the day of the year. %H is the hour on a 24-hour clock, %I is on a 12-hour clock, %k is like %H -- 2.39.5