diff mbox

manual/time.texi: TZ and zoneinfo updates

Message ID 54B98B3E.4020400@gmx.com
State Dropped
Headers show

Commit Message

J William Piggott Jan. 16, 2015, 10:05 p.m. UTC
Update the manual regarding the use of the TZ
environment variable and that the zoneinfo data is
no longer installed by glibc.

Signed-off-by: J William Piggott <elseifthen@gmx.com>

The following changes since commit 026eb207eda8cc93f6f7f0980f0a8e51587d8011:

  S390: Get rid of linknamespace failures for utmp functions. (2015-01-16 09:18:58 +0100)

are available in the git repository at:

  git@github.com:jwpi/glibc.git time

for you to fetch changes up to 30b60e63821928e11208e6319fd05ca0c39248a7:

  manual/time.texi: TZ and zoneinfo updates (2015-01-16 15:34:50 -0500)

Change log:

2015-01-16  J William Piggott  <elseifthen@gmx.com>

	* manual/search.texi: TZ and zoneinfo updates

 manual/time.texi | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)
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diff --git a/manual/time.texi b/manual/time.texi
index 8a5f94e..5aaa042 100644
--- a/manual/time.texi
+++ b/manual/time.texi
@@ -403,8 +403,11 @@  represents an elapsed time.  When interpreted as a calendar time value,
 it represents the number of seconds elapsed since 00:00:00 on January 1,
 1970, Coordinated Universal Time.  (This calendar time is sometimes
 referred to as the @dfn{epoch}.)  POSIX requires that this count not
-include leap seconds, but on some systems this count includes leap seconds
-if you set @code{TZ} to certain values (@pxref{TZ Variable}).
+include leap seconds. On nonstandard systems where this count includes
+leap seconds, the system must be configured to use the ``right'' (now
+called leaps) timezone database by replacing all of the files in the
+root of the ``zoneinfo'' directory with the ``right'' timezone files in
+order to output the correct civil timescales (@pxref{TZ Variable}).
 Note that a simple time has no concept of local time zone.  Calendar
 Time @var{T} is the same instant in time regardless of where on the
@@ -2358,6 +2361,9 @@  set @code{TZ} if you are using a computer over a network from a
 different time zone, and would like times reported to you in the time
 zone local to you, rather than what is local to the computer.
+If the @code{TZ} environment variable is set to a value that @theglibc{}
+cannot interpret correctly then UTC will be used by default.
 In POSIX.1 systems the value of the @code{TZ} variable can be in one of
 three formats.  With @theglibc{}, the most common format is the
 last one, which can specify a selection from a large database of time
@@ -2500,7 +2506,7 @@  zone.
 @pindex /etc/localtime
 @pindex localtime
-If the @code{TZ} environment variable does not have a value, the
+If the @code{TZ} environment variable is not set, the
 operation chooses a time zone by default.  In @theglibc{}, the
 default time zone is like the specification @samp{TZ=:/etc/localtime}
 (or @samp{TZ=:/usr/local/etc/localtime}, depending on how @theglibc{}
@@ -2509,20 +2515,22 @@  rule for choosing the default time zone, so there is little we can say
 about them.
 @cindex time zone database
-@pindex /share/lib/zoneinfo
+@pindex /usr/share/zoneinfo
 @pindex zoneinfo
 If @var{characters} begins with a slash, it is an absolute file name;
 otherwise the library looks for the file
-@w{@file{/share/lib/zoneinfo/@var{characters}}}.  The @file{zoneinfo}
+@w{@file{/usr/share/zoneinfo/@var{characters}}}.  The @file{zoneinfo}
 directory contains data files describing local time zones in many
 different parts of the world.  The names represent major cities, with
 subdirectories for geographical areas; for example,
 @file{America/New_York}, @file{Europe/London}, @file{Asia/Hong_Kong}.
 These data files are installed by the system administrator, who also
 sets @file{/etc/localtime} to point to the data file for the local time
-zone.  @Theglibc{} comes with a large database of time zone
+zone.  @Theglibc{} is compatible with The IANA Time Zone Database,
+sometimes called tz, or zoneinfo.  This is  a large database of time zone
 information for most regions of the world, which is maintained by a
-community of volunteers and put in the public domain.
+community of volunteers and put in the public domain.  It is located at
 @node Time Zone Functions
 @subsection Functions and Variables for Time Zones