[tz] [PATCH 2/3] Replace some zones with links when that doesn't lose non-LMT info.

Paul Eggert eggert at cs.ucla.edu
Thu Sep 5 02:09:52 UTC 2013


Steve Allen wrote:
> Unlike UTC, the concept of UT can be validly extended into the
> indefinite past.

Thanks for bringing this up.  Here's a proposed patch that
tries to fix the occurrences of this problem that I found in
the tz code and data.  I've pushed this to the experimental
repository.

>From 42801d2b1fb0a644096c228daec1be20278d9bd0 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert at cs.ucla.edu>
Date: Wed, 4 Sep 2013 19:07:31 -0700
Subject: [PATCH] Correct some UTC-vs-UT solecisms.

In several places the code and documentation incorrectly used
"UTC" to describe time stamps that might precede the introduction
of UTC and for which UTC is therefore undefined.  Change these
uses to "UT", as that's the correct term when talking about these
time stamps.  Problem reported by Steve Allen in
<http://mm.icann.org/pipermail/tz/2013-September/019907.html>.
The major compatibility issue here is with 'zdump -v'; it'll now
output "UT" instead of the possibly-incorrect "UTC".
Many files change in minor ways in the commentary.
* zdump.c (show):
* zic.c (inzsub, addtype):
In output, say "UT" rather than "UTC", since the time stamp we're
talking about might precede the introduction of UTC.
---
 Makefile      |  4 ++--
 Theory        |  8 ++++----
 australasia   |  2 +-
 date.1        |  2 +-
 date.c        |  2 +-
 etcetera      |  4 ++--
 europe        |  4 ++--
 localtime.c   | 12 ++++++------
 newctime.3    |  4 ++--
 newstrftime.3 |  4 ++--
 newtzset.3    |  5 +++--
 strftime.c    |  2 +-
 tzfile.5      |  8 ++++----
 tzfile.h      |  4 ++--
 zdump.c       |  2 +-
 zic.8         | 12 ++++++------
 zic.c         |  6 +++---
 17 files changed, 43 insertions(+), 42 deletions(-)

diff --git a/Makefile b/Makefile
index e439055..41b6ffc 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ LOCALTIME=	GMT
 # time zone files, or adding it to a time zone file).
 # (When a POSIX-style environment variable is handled, the rules in the
 # template file are used to determine "spring forward" and "fall back" days and
-# times; the environment variable itself specifies UTC offsets of standard and
+# times; the environment variable itself specifies UT offsets of standard and
 # summer time.)
 # Alternately, if you discover you've got the wrong time zone, you can just
 #	zic -p rightzone
@@ -196,7 +196,7 @@ GCC_DEBUG_FLAGS = -Dlint -g3 -O3 -fno-common -fstrict-aliasing \
 # that gives an offset to add to the time_t when converting it.
 # "timelocal" is equivalent to "mktime".
 # "timegm" is like "timelocal" except that it turns a struct tm into
-# a time_t using UTC (rather than local time as "timelocal" does).
+# a time_t using UT (rather than local time as "timelocal" does).
 # "timeoff" is like "timegm" except that it accepts a second (long) argument
 # that gives an offset to use when converting to a time_t.
 # "posix2time" and "time2posix" are described in an included manual page.
diff --git a/Theory b/Theory
index ea2d004..39ef7ac 100644
--- a/Theory
+++ b/Theory
@@ -43,7 +43,7 @@ POSIX has the following properties and limitations.
 		"+" and "-" in the names.
 	offset
 		is of the form '[+-]hh:[mm[:ss]]' and specifies the
-		offset west of UTC.  'hh' may be a single digit; 0<=hh<=24.
+		offset west of UT.  'hh' may be a single digit; 0<=hh<=24.
 		The default DST offset is one hour ahead of standard time.
 	date[/time],date[/time]
 		specifies the beginning and end of DST.  If this is absent,
@@ -189,7 +189,7 @@ Points of interest to folks with other systems:
 	but this functionality was removed in later versions of BSD.
 
 *	In SVR2, time conversion fails for near-minimum or near-maximum
-	time_t values when doing conversions for places that don't use UTC.
+	time_t values when doing conversions for places that don't use UT.
 	This package takes care to do these conversions correctly.
 
 The functions that are conditionally compiled if STD_INSPIRED is defined
@@ -428,14 +428,14 @@ in decreasing order of importance:
 	Use 'LMT' for local mean time of locations before the introduction
 		of standard time; see "Scope of the tz database".
 
-	Use UTC (with time zone abbreviation 'zzz') for locations while
+	Use UT (with time zone abbreviation 'zzz') for locations while
 		uninhabited.  The 'zzz' mnemonic is that these locations are,
 		in some sense, asleep.
 
 Application writers should note that these abbreviations are ambiguous
 in practice: e.g. 'EST' has a different meaning in Australia than
 it does in the United States.  In new applications, it's often better
-to use numeric UTC offsets like '-0500' instead of time zone
+to use numeric UT offsets like '-0500' instead of time zone
 abbreviations like 'EST'; this avoids the ambiguity.
 
 
diff --git a/australasia b/australasia
index 74ebee2..3e1bfc6 100644
--- a/australasia
+++ b/australasia
@@ -736,7 +736,7 @@ Zone Pacific/Funafuti	11:56:52 -	LMT	1901
 # 1886-1891; Baker was similar but exact dates are not known.
 # Inhabited by civilians 1935-1942; U.S. military bases 1943-1944;
 # uninhabited thereafter.
-# Howland observed Hawaii Standard Time (UTC-10:30) in 1937;
+# Howland observed Hawaii Standard Time (UT-10:30) in 1937;
 # see page 206 of Elgen M. Long and Marie K. Long,
 # Amelia Earhart: the Mystery Solved, Simon & Schuster (2000).
 # So most likely Howland and Baker observed Hawaii Time from 1935
diff --git a/date.1 b/date.1
index 7957f74..72c44d0 100644
--- a/date.1
+++ b/date.1
@@ -134,7 +134,7 @@ the seconds part of the new time; if no seconds are given, zero is assumed.
 These options are available:
 .TP
 .BR \-u " or " \-c
-Use UTC when setting and showing the date and time.
+Use Universal Time when setting and showing the date and time.
 .TP
 .BI "\-r " seconds
 Output the date that corresponds to
diff --git a/date.c b/date.c
index d8ff50e..fe1311a 100644
--- a/date.c
+++ b/date.c
@@ -118,7 +118,7 @@ main(const int argc, char *argv[])
 		switch (ch) {
 		default:
 			usage();
-		case 'u':		/* do it in UTC */
+		case 'u':		/* do it in UT */
 		case 'c':
 			dogmt();
 			break;
diff --git a/etcetera b/etcetera
index a9ff729..9ba7f7b 100644
--- a/etcetera
+++ b/etcetera
@@ -31,9 +31,9 @@ Link	Etc/GMT				Etc/GMT0
 # even though this is the opposite of what many people expect.
 # POSIX has positive signs west of Greenwich, but many people expect
 # positive signs east of Greenwich.  For example, TZ='Etc/GMT+4' uses
-# the abbreviation "GMT+4" and corresponds to 4 hours behind UTC
+# the abbreviation "GMT+4" and corresponds to 4 hours behind UT
 # (i.e. west of Greenwich) even though many people would expect it to
-# mean 4 hours ahead of UTC (i.e. east of Greenwich).
+# mean 4 hours ahead of UT (i.e. east of Greenwich).
 #
 # In the draft 5 of POSIX 1003.1-200x, the angle bracket notation allows for
 # TZ='<GMT-4>+4'; if you want time zone abbreviations conforming to
diff --git a/europe b/europe
index 4f972a5..04f61d9 100644
--- a/europe
+++ b/europe
@@ -1863,7 +1863,7 @@ Zone	Europe/Oslo	0:43:00 -	LMT	1895 Jan  1
 # before 1895, and therefore probably changed the local time somewhere
 # between 1895 and 1925 (inclusive).
 
-# From Paul Eggert (2013-09-02):
+# From Paul Eggert (2013-09-04):
 #
 # Actually, Jan Mayen was never occupied by Germany during World War II,
 # so it must have diverged from Oslo time during the war, as Oslo was
@@ -1874,7 +1874,7 @@ Zone	Europe/Oslo	0:43:00 -	LMT	1895 Jan  1
 # 1941 with a small Norwegian garrison and continued operations despite
 # frequent air ttacks from Germans.  In 1943 the Americans established a
 # radiolocating station on the island, called "Atlantic City".  Possibly
-# the UTC offset changed during the war, but I think it unlikely that
+# the UT offset changed during the war, but I think it unlikely that
 # Jan Mayen used German daylight-saving rules.
 #
 # Svalbard is more complicated, as it was raided in August 1941 by an
diff --git a/localtime.c b/localtime.c
index a0a4e5e..619a656 100644
--- a/localtime.c
+++ b/localtime.c
@@ -77,11 +77,11 @@ static const char	gmt[] = "GMT";
 #endif /* !defined TZDEFDST */
 
 struct ttinfo {				/* time type information */
-	int_fast32_t	tt_gmtoff;	/* UTC offset in seconds */
+	int_fast32_t	tt_gmtoff;	/* UT offset in seconds */
 	int		tt_isdst;	/* used to set tm_isdst */
 	int		tt_abbrind;	/* abbreviation list index */
 	int		tt_ttisstd;	/* TRUE if transition is std time */
-	int		tt_ttisgmt;	/* TRUE if transition is UTC */
+	int		tt_ttisgmt;	/* TRUE if transition is UT */
 };
 
 struct lsinfo {				/* leap second information */
@@ -842,7 +842,7 @@ getrule(const char *strp, register struct rule *const rulep)
 
 /*
 ** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
-** year, a rule, and the offset from UTC at the time that rule takes effect,
+** year, a rule, and the offset from UT at the time that rule takes effect,
 ** calculate the Epoch-relative time that rule takes effect.
 */
 
@@ -925,10 +925,10 @@ transtime(const time_t janfirst, const int year,
 	}
 
 	/*
-	** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
+	** "value" is the Epoch-relative time of 00:00:00 UT on the day in
 	** question. To get the Epoch-relative time of the specified local
 	** time on that day, add the transition time and the current offset
-	** from UTC.
+	** from UT.
 	*/
 	return value + rulep->r_time + offset;
 }
@@ -1379,7 +1379,7 @@ gmtsub(const time_t *const timep, const int_fast32_t offset,
 #ifdef TM_ZONE
 	/*
 	** Could get fancy here and deliver something such as
-	** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
+	** "UT+xxxx" or "UT-xxxx" if offset is non-zero,
 	** but this is no time for a treasure hunt.
 	*/
 	if (offset != 0)
diff --git a/newctime.3 b/newctime.3
index 3583a91..8528deb 100644
--- a/newctime.3
+++ b/newctime.3
@@ -165,7 +165,7 @@ includes the following fields:
 	int tm_yday;	/\(** day of year (0 - 365) \(**/
 	int tm_isdst;	/\(** is summer time in effect? \(**/
 	char \(**tm_zone;	/\(** abbreviation of timezone name \(**/
-	long tm_gmtoff;	/\(** offset from UTC in seconds \(**/
+	long tm_gmtoff;	/\(** offset from UT in seconds \(**/
 .fi
 .RE
 .PP
@@ -184,7 +184,7 @@ is non-zero if summer time is in effect.
 .PP
 .I Tm_gmtoff
 is the offset (in seconds) of the time represented
-from UTC, with positive values indicating east
+from UT, with positive values indicating east
 of the Prime Meridian.
 .SH FILES
 .ta \w'/usr/local/etc/zoneinfo/posixrules\0\0'u
diff --git a/newstrftime.3 b/newstrftime.3
index ef79e4d..5b0dcdc 100644
--- a/newstrftime.3
+++ b/newstrftime.3
@@ -164,7 +164,7 @@ using AM/PM notation.
 is replaced by the second as a decimal number (00-60).
 .TP
 %s
-is replaced by the number of seconds since the Epoch, UTC (see mktime(3)).
+is replaced by the number of seconds since the Epoch, UT (see mktime(3)).
 .TP
 %T
 is replaced by the time in the format %H:%M:%S.
@@ -211,7 +211,7 @@ is replaced by the time zone name,
 or by the empty string if this is not determinable.
 .TP
 %z
-is replaced by the offset from UTC in the format +HHMM or -HHMM as appropriate,
+is replaced by the offset from UT in the format +HHMM or -HHMM as appropriate,
 with positive values representing locations east of Greenwich,
 or by the empty string if this is not determinable.
 .TP
diff --git a/newtzset.3 b/newtzset.3
index fd6b677..8162920 100644
--- a/newtzset.3
+++ b/newtzset.3
@@ -26,8 +26,9 @@ in the system time conversion information directory, is used by
 If
 .B TZ
 appears in the environment but its value is a null string,
-Coordinated Universal Time (UTC) is used (without leap second
-correction).  If
+Universal Time (UT) is used, with the abbreviation "UTC"
+and without leap second
+correction.  If
 .B TZ
 appears in the environment and its value is not a null string:
 .IP
diff --git a/strftime.c b/strftime.c
index 821ce7f..aba3d33 100644
--- a/strftime.c
+++ b/strftime.c
@@ -501,7 +501,7 @@ label:
 				diff = t->TM_GMTOFF;
 #else /* !defined TM_GMTOFF */
 				/*
-				** C99 says that the UTC offset must
+				** C99 says that the UT offset must
 				** be computed by looking only at
 				** tm_isdst. This requirement is
 				** incorrect, since it means the code
diff --git a/tzfile.5 b/tzfile.5
index 10698a2..e92eaed 100644
--- a/tzfile.5
+++ b/tzfile.5
@@ -20,7 +20,7 @@ These values are,
 in order:
 .TP
 .I tzh_ttisgmtcnt
-The number of UTC/local indicators stored in the file.
+The number of UT/local indicators stored in the file.
 .TP
 .I tzh_ttisstdcnt
 The number of standard/wall indicators stored in the file.
@@ -83,7 +83,7 @@ and a one-byte value for
 .IR tt_abbrind .
 In each structure,
 .I tt_gmtoff
-gives the number of seconds to be added to UTC,
+gives the number of seconds to be added to UT,
 .I tt_isdst
 tells whether
 .I tm_isdst
@@ -118,9 +118,9 @@ time zone environment variables.
 .PP
 Finally there are
 .I tzh_ttisgmtcnt
-UTC/local indicators, each stored as a one-byte value;
+UT/local indicators, each stored as a one-byte value;
 they tell whether the transition times associated with local time types
-were specified as UTC or local time,
+were specified as UT or local time,
 and are used when a time zone file is used in handling POSIX-style
 time zone environment variables.
 .PP
diff --git a/tzfile.h b/tzfile.h
index d04fe04..0cf2943 100644
--- a/tzfile.h
+++ b/tzfile.h
@@ -55,7 +55,7 @@ struct tzhead {
 **	tzh_timecnt (char [4])s		coded transition times a la time(2)
 **	tzh_timecnt (unsigned char)s	types of local time starting at above
 **	tzh_typecnt repetitions of
-**		one (char [4])		coded UTC offset in seconds
+**		one (char [4])		coded UT offset in seconds
 **		one (unsigned char)	used to set tm_isdst
 **		one (unsigned char)	that's an abbreviation list index
 **	tzh_charcnt (char)s		'\0'-terminated zone abbreviations
@@ -68,7 +68,7 @@ struct tzhead {
 **					if absent, transition times are
 **					assumed to be wall clock time
 **	tzh_ttisgmtcnt (char)s		indexed by type; if TRUE, transition
-**					time is UTC, if FALSE,
+**					time is UT, if FALSE,
 **					transition time is local time
 **					if absent, transition times are
 **					assumed to be local time
diff --git a/zdump.c b/zdump.c
index 3d5ec64..2a9860c 100644
--- a/zdump.c
+++ b/zdump.c
@@ -628,7 +628,7 @@ show(char *zone, time_t t, int v)
 			(void) printf(tformat(), t);
 		} else {
 			dumptime(tmp);
-			(void) printf(" UTC");
+			(void) printf(" UT");
 		}
 		(void) printf(" = ");
 	}
diff --git a/zic.8 b/zic.8
index d0d34ce..5c8b59c 100644
--- a/zic.8
+++ b/zic.8
@@ -288,13 +288,13 @@ This is the name used in creating the time conversion information file for the
 zone.
 .TP
 .B GMTOFF
-The amount of time to add to UTC to get standard time in this zone.
+The amount of time to add to UT to get standard time in this zone.
 This field has the same format as the
 .B AT
 and
 .B SAVE
 fields of rule lines;
-begin the field with a minus sign if time must be subtracted from UTC.
+begin the field with a minus sign if time must be subtracted from UT.
 .TP
 .B RULES/SAVE
 The name of the rule(s) that apply in the time zone or,
@@ -315,10 +315,10 @@ a slash (/)
 separates standard and daylight abbreviations.
 .TP
 .B UNTILYEAR [MONTH [DAY [TIME]]]
-The time at which the UTC offset or the rule(s) change for a location.
+The time at which the UT offset or the rule(s) change for a location.
 It is specified as a year, a month, a day, and a time of day.
 If this is specified,
-the time zone information is generated from the given UTC offset
+the time zone information is generated from the given UT offset
 and rule change until the time specified.
 The month, day, and time of day have the same format as the IN, ON, and AT
 fields of a rule; trailing fields can be omitted, and default to the
@@ -485,9 +485,9 @@ If,
 for a particular zone,
 a clock advance caused by the start of daylight saving
 coincides with and is equal to
-a clock retreat caused by a change in UTC offset,
+a clock retreat caused by a change in UT offset,
 .IR zic
-produces a single transition to daylight saving at the new UTC offset
+produces a single transition to daylight saving at the new UT offset
 (without any change in wall clock time).
 To get separate transitions
 use multiple zone continuation lines
diff --git a/zic.c b/zic.c
index 1715c4a..97786ae 100644
--- a/zic.c
+++ b/zic.c
@@ -1005,7 +1005,7 @@ inzsub(register char **const fields, const int nfields, const int iscont)
 	}
 	z.z_filename = filename;
 	z.z_linenum = linenum;
-	z.z_gmtoff = gethms(fields[i_gmtoff], _("invalid UTC offset"), TRUE);
+	z.z_gmtoff = gethms(fields[i_gmtoff], _("invalid UT offset"), TRUE);
 	if ((cp = strchr(fields[i_format], '%')) != 0) {
 		if (*++cp != 's' || strchr(cp, '%') != 0) {
 			error(_("invalid abbreviation format"));
@@ -2079,7 +2079,7 @@ wp = ecpyalloc(_("no POSIX environment variable for zone"));
 				INITIALIZE(ktime);
 				if (useuntil) {
 					/*
-					** Turn untiltime into UTC
+					** Turn untiltime into UT
 					** assuming the current gmtoff and
 					** stdoff values.
 					*/
@@ -2253,7 +2253,7 @@ addtype(const zic_t gmtoff, const char *const abbr, const int isdst,
 		exit(EXIT_FAILURE);
 	}
 	if (! (-1L - 2147483647L <= gmtoff && gmtoff <= 2147483647L)) {
-		error(_("UTC offset out of range"));
+		error(_("UT offset out of range"));
 		exit(EXIT_FAILURE);
 	}
 	gmtoffs[i] = gmtoff;
-- 
1.8.1.2




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