tzset.3: ffix

[thirdparty/man-pages.git] / man3 / tzset.3

diff --git a/man3/tzset.3 b/man3/tzset.3
index c6c2433e2393989a2ae8afe079db7c36248750bc..845f6283e4944772349a53d2f3d5c8287cf795b3 100644 (file)
--- a/man3/tzset.3
+++ b/man3/tzset.3
@@ -30,36 +30,36 @@
 .\" Modified 2001-11-13, aeb
 .\" Modified 2004-12-01 mtk and Martin Schulze <joey@infodrom.org>
 .\"
-.TH TZSET 3  2015-03-29 "" "Linux Programmer's Manual"
+.TH TZSET 3  2017-09-15 "" "Linux Programmer's Manual"
 .SH NAME
 tzset, tzname, timezone, daylight \- initialize time conversion information
 .SH SYNOPSIS
 .nf
 .B #include <time.h>
-.sp
+.PP
 .B void tzset (void);
-.sp
+.PP
 .BI "extern char *" tzname [2];
 .BI "extern long " timezone ;
 .BI "extern int " daylight ;
 .fi
-.sp
+.PP
 .in -4n
 Feature Test Macro Requirements for glibc (see
 .BR feature_test_macros (7)):
 .in
-.sp
+.PP
 .BR tzset ():
-_POSIX_C_SOURCE\ >=\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE
+_POSIX_C_SOURCE
 .br
 .IR tzname :
-_POSIX_C_SOURCE\ >=\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE
-.br
-.IR timezone :
-_SVID_SOURCE || _XOPEN_SOURCE
+_POSIX_C_SOURCE
 .br
+.IR timezone ,
 .IR daylight :
-_SVID_SOURCE || _XOPEN_SOURCE
+_XOPEN_SOURCE
+    || /* Glibc since 2.19: */ _DEFAULT_SOURCE
+    || /* Glibc versions <= 2.19: */ _SVID_SOURCE
 .SH DESCRIPTION
 The
 .BR tzset ()
@@ -70,14 +70,15 @@ This function is automatically called by the
 other time conversion functions that depend on the timezone.
 In a System-V-like environment, it will also set the variables \fItimezone\fP
 (seconds West of UTC) and \fIdaylight\fP (to 0 if this timezone does not
-have any daylight saving time rules, or to nonzero if there is a time during
-the year when daylight saving time applies).
+have any daylight saving time rules, or to nonzero if there is a time,
+past, present or future when daylight saving time applies).
 .PP
 If the
 .B TZ
 variable does not appear in the environment, the system timezone is used.
 The system timezone is configured by copying, or linking, a file in the
-.BR tzfile "(5) format to"
+.BR tzfile (5)
+format to
 .IR /etc/localtime .
 A timezone database of these files may be located in the system
 timezone directory (see the \fBFILES\fP section below).
@@ -93,11 +94,13 @@ The value of
 can be one of two formats.
 The first format is a string of characters that directly represent the
 timezone to be used:
-.sp
-.RS
+.PP
+.in +4n
+.EX
 .IR "std offset" [ dst [ offset ][, start [ /time ], end [ /time ]]]
-.RE
-.sp
+.EE
+.in
+.PP
 There are no spaces in the specification.
 The \fIstd\fP string specifies an abbreviation for the timezone and must be
 three or more alphabetic characters.
@@ -111,11 +114,12 @@ The \fIoffset\fP is positive
 if the local timezone is west of the Prime Meridian and negative if it is
 east.
 The hour must be between 0 and 24, and the minutes and seconds 00 and 59:
-.sp
-.RS
+.PP
+.in +4n
+.EX
 .RI [ + | - ] hh [ :mm [ :ss ]]
-.RE
-.sp
+.EE
+.in
 .PP
 The \fIdst\fP string and \fIoffset\fP specify the name and offset for the
 corresponding daylight saving timezone.
@@ -148,24 +152,28 @@ Day 0 is a Sunday.
 The \fItime\fP fields specify when, in the local time currently in effect,
 the change to the other time occurs.
 If omitted, the default is 02:00:00.
-
+.PP
 Here is an example for New Zealand,
 where the standard time (NZST) is 12 hours ahead of UTC,
 and daylight saving time (NZDT), 13 hours ahead of UTC,
 runs from the first Sunday in October to the third Sunday in March,
 and the changeovers happen at the default time of 02:00:00:
-.nf
-
-    TZ="NZST-12:00:00NZDT-13:00:00,M10.1.0,M3.3.0"
-.fi
+.PP
+.in +4n
+.EX
+TZ="NZST-12:00:00NZDT-13:00:00,M10.1.0,M3.3.0"
+.EE
+.in
 .PP
 The second format specifies that the timezone information should be read
 from a file:
-.sp
-.RS
+.PP
+.in +4n
+.EX
 :[filespec]
-.RE
-.sp
+.EE
+.in
+.PP
 If the file specification \fIfilespec\fP is omitted, or its value cannot
 be interpreted, then Coordinated Universal Time (UTC) is used.
 If \fIfilespec\fP is given, it specifies another
@@ -177,10 +185,12 @@ If the colon is omitted each
 of the above \fBTZ\fP formats will be tried.
 .PP
 Here's an example, once more for New Zealand:
-.nf
-
-    TZ=":Pacific/Auckland"
-.fi
+.PP
+.in +4n
+.EX
+TZ=":Pacific/Auckland"
+.EE
+.in
 .SH ENVIRONMENT
 .TP
 .B TZ
@@ -202,7 +212,8 @@ The system timezone database directory.
 When a TZ string includes a dst timezone without anything following it,
 then this file is used for the start/end rules.
 It is in the
-.BR tzfile "(5) format."
+.BR tzfile (5)
+format.
 By default, the zoneinfo Makefile hard links it to the
 .IR America/New_York " tzfile."
 .PP
@@ -221,15 +232,9 @@ T{
 T}     Thread safety   MT-Safe env locale
 .TE
 .SH CONFORMING TO
-SVr4, POSIX.1-2001, 4.3BSD.
+POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD.
 .SH NOTES
-Note that the variable \fIdaylight\fP does not indicate that daylight
-saving time applies right now.
-It used to give the number of some
-algorithm (see the variable \fItz_dsttime\fP in
-.BR gettimeofday (2)).
-It has been obsolete for many years but is required by SUSv2.
-.LP
+.PP
 4.3BSD had a function
 .BI "char *timezone(" zone ", " dst )
 that returned the