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.
These come from POSIX or similar platforms, or from the standard
'zic' implementation, but never got written down anywhere.
* Theory: Document other POSIX-inspired restrictions on names.
* zic.8 (DESCRIPTION): Document that zic's behavior is unspecified
if some names are duplicates. Sometimes it complains, sometimes not.
* northamerica (America/Anguilla, America/Dominica, America/Grenada)
(America/Guadeloupe, America/Montserrat, America/St_Kitts)
(America/St_Lucia, America/St_Vincent, America/Tortola)
(America/St_Thomas):
Link to America/Port_of_Spain instead of having a separate zone
that differs only in LMT. Each LMT entry is just a placeholder for
unavailable info, and by itself does not justify a separate zone.
Using just one zone simplifies maintenance, makes the runtime
a bit smaller, and can help simplify user selection of zones.
* southamerica (America/Aruba): Likewise, for America/Curacao.
* backward (America/Virgin):
* northamerica (America/St_Barthelemy, America/Marigot):
Adjust to the other changes, by not linking to a link.
This should allay concerns that the links would go away any time soon.
Suggested by Stephen Colebourne in
<http://mm.icann.org/pipermail/tz/2013-September/019801.html>.
Change "`" to "'"; these days, "`" and "'" are not symmetric.
* antarctica (Antarctica/McMurdo):
* europe (Europe/Jersey, Europe/Guernsey, Europe/Isle_of_Man)
(Europe/Mariehamn, Europe/Busingen, Europe/Vatican, Europe/San_Marino)
(Arctic/Longyearbyen, Europe/Ljubljana, Europe/Podgorica)
(Europe/Sarajevo, Europe/Skopje, Europe/Zagreb, Europe/Bratislava):
* northamerica (America/St_Barthelemy, America/Marigot):
* southamerica (America/Lower_Princes, America/Kralendijk):
Move here from 'backward'. This reverts a 2013-08-09 change.
Other tz file readers had problems with the new pre1970 file, so
remove it and related changes. To recover the pre-1970 data,
instead change pre-1970 Zone entries in other files back to what
they were. Perhaps we'll try to find a better way someday.
* .gitignore: Remove back-pre1970.
* Makefile (BACKWARD): Remove. All uses changed back to 'backward'.
(AWK_SCRIPTS): Remove back-pre1970.awk.
(back-pre1970): Remove.
(clean_misc): Don't rm back-pre1970.
(check_public): Remove special case for pre1970.
* back-pre1970.awk, pre1970: Remove.
* backward (America/Anguilla, America/Antigua, America/Aruba)
(America/Atikokan, America/Blanc-Sablon, America/Cayman)
(America/Creston, America/Curacao, America/Dominica, America/Grenada)
(America/Guadeloupe, America/Montreal, America/Montserrat)
(America/Nassau, America/Port_of_Spain, America/St_Kitts)
(America/St_Lucia, America/St_Thomas, America/St_Vincent)
(America/Tortola): Remove, as these are zones again.
(America/Coral_Harbour, America/Kralendijk, America/Lower_Princes)
(America/Marigot, America/St_Barthelemy, America/Virgin):
Revert to previous links.
* northamerica (Mont, America/Blanc-Sablon, America/Montreal)
(America/Atikokan, America/Creston, America/Anguilla, America/Antigua)
(Bahamas, America/Nassau, America/Cayman, America/Dominica)
(America/Grenada, America/Guadeloupe, America/Montserrat)
(America/St_Kitts, America/St_Lucia, America/St_Vincent)
(America/Tortola, America/St_Thomas):
* southamerica (America/Aruba, America/Curacao, America/Port_of_Spain):
Restore these rules and zones.
* .gitignore: Add back-pre1970.
This lets us preserve information about pre-1970 time stamps when
we change a Zone to a Link to another zone whose time stamps agree
after 1970. This should address concerns about some recent
changes that removed this information. This implementation is a
stripped-down version of a suggestion by Andrew Main (Zefram) in
<http://mm.icann.org/pipermail/tz/2013-August/019615.html> and
<http://mm.icann.org/pipermail/tz/2013-August/019639.html> to
allow filtering tz data by date range. Unlike Zefram's
suggestion, this implementation supports only two date ranges,
namely 1970 on, using 'make BACKWARD=backward'; and all dates,
using 'make BACKWARD="pre1970 back-pre1970"'. At some point I'd
like to improve it to support arbitrary date ranges, but at least
we've now restored the data whose loss was of some concern.
* .gitignore: Add back-pre1970.
* Makefile (BACKWARD): New macro.
(YDATA): Use it instead of 'backward'.
(AWK_SCRIPTS): New macro, with additional script back-pre1970.awk.
(MISC): Use it.
(back-pre1970): New rule.
(clean_misc): Clean back-pre1970. Also clean time.tab, while we're
at it.
(check_public): Don't require pre1970 to stand alone.
* pre1970, back-pre1970.awk: New files.
This is like the previous change, except it entails a change to zone.tab.
The America/Montreal entry was created only because we mistakenly
thought that Montreal's and Toronto's post-1970 time stamps differed.
* backward, northamerica (America/Montreal):
Now a 'backward' link to America/Toronto.
* northamerica (Mont): Remove rules; no longer needed.
(America/Thunder_Bay): Refer to Toronto rules, not Mont.
This doesn't change any time stamps.
* zone.tab (America/Montreal): Remove.
(America/Toronto): Say that it also covers most of Quebec.
This continues in the series of moving entries to 'backward' if
they exist only because of obsolete tz rules about country codes.
In this case, Zone entries are changed to Links; this doesn't
affect any post-1970 time stamps, and the pre-1970 time stamps
are out of scope and are often of dubious reliability.
* backward, northamerica, southamerica (America/Anguilla)
(America/Antigua, America/Aruba, America/Blanc-Sablon)
(America/Cayman, America/Curacao, America/Dominica)
(America/Grenada, America/Guadeloupe, America/Montserrat)
(America/Port_of_Spain, America/St_Kitts, America/St_Lucia)
(America/St_Thomas, America/St_Vincent, America/Tortola):
Now 'backward' links to America/Puerto_Rico.
(America/Atikokan): Now a 'backward' link to America/Panama.
(America/Creston): Now a 'backward' link to America/Phoenix.
(America/Nassau): Now a 'backward' link to America/Toronto.
* backward (America/Coral_Harbour, America/Kralendijk)
(America/Lower_Princes, America/Marigot, America/St_Barthelemy)
(America/Virgin): Adjust to avoid link-to-a-link.
This fixes the 2013-08-15 change so that 'make check' works again.
* backward (America/Shiprock): Move this link here....
* northamerica (America/Shiprock): ... to here.
* tzselect.ksh (LC_ALL): Don't set this, so that the user can
use the locale's decimal point in coordinates.
(convert_coord): Rename from cvt1. All callers changed.
Support more ISO 6709 forms.
* tzselect.8: Document -c better, including the new forms.
These let the user select TZ based on geographical coordinates.
Combining '-c COORD' with '-t time' better insulates the user from
issues of nationality.
* tzselect.8 (SYNOPSIS, OPTIONS): Document the new options.
* tzselect.ksh: Implement them, using the great-circle special
case of the Vicenty formula for distances on ellipsoids.
(LC_ALL): Set to C, since tzselect is English only. That way, we
treat decimal-points in -c option operands the same in all environments.
(usage): Document new options. Document existing ones better.
(output_distances): New variable.
(main): Don't assume SECSPERDAY <= INT_MAX here, since we try
not to assume that sort of thing elsewhere in this file.
Don't rely on undefined behavior in the weird case where
cuthitime < absolute_min_time + SECSPERDAY / 2.
This is a backwards-compatible way of transitioning to a less
politically-charged approach to choosing TZ values. A new time
zone table time.tab acts like zone.tab, except it omits TZ values
that are present only for political reasons. tzselect has a new
"-t zonetabtype" option that lets users select which time zone table
to use, and installers can select the default table. The zone.tab
file does not change, and the default tzselect table for now is
zone.tab. This avoids the backward-compatibility concerns
expressed on the tz mailing list; see, for example,
the discussion surrounding Derick Rethans's comments in
<http://mm.icann.org/pipermail/tz/2013-August/019544.html>
* .gitignore: Add time.tab.
* Makefile (ZONETABTYPE): New macro.
(TABDATA): Add time.tab.
(all): Depend on $(TABDATA).
(install): Do not depend on $(TABDATA), since $(DATA) includes it.
Install time.tab too.
(time.tab): New rule.
(tzselect.tab): Substitute ZONETABTYPE.
* zone-time.awk: New file.
* tzselect.8: Document new options, and --help and --version while
we're at it.
* tzselect.ksh (ZONETABTYPE): New var.
Implement -t ZONETABTYPE option.
Check that no extra operands are given.
* zone.tab: Change first comment line, to distinguish the two
tables better.
This unnecessary duplicate of America/Denver was confusing, as it
incorrectly implied that 'Mountain Time - Navajo' differed from
'Mountain Time' either now or in the past. Clarify this in a
better way, by mentioning in the Arizona entry that it doesn't
include Navajo.
On my platform (Ubuntu 13.04 x86-64, Xeon E3-1225 V2), this sped up
'zdump -V -c 2147483647,2147483648 America/Los_Angeles'
from 13.880 to 0.000 seconds user+system time.
(INTMAX_MAX): Define if the system doesn't.
(SECSPER400YEARS): New macro.
(SECSPER400YEARS_FITS): New constant.
(yeartot): Speed up by using division instead of
repeated subtraction.
* iso3166.tab, zone.tab: Make it clear that country codes aren't
necessarily for countries. Thanks to Derick Rethans for spotting this.
* zone.tab (Antarctica/McMurdo, Europe/Mariehamn, Europe/Sarajevo)
(America/St_Barthelemy, America/Kralendijk, Europe/Busingen)
(Europe/Guernsey, Europe/Zagreb, Europe/Isle_of_Man, Europe/Jersey)
(Europe/Podgorica, America/Marigot, Europe/Skopje, Europe/Ljubljana)
(Arctic/Longyearbyen, Europe/Bratislava, Europe/San_Marino)
(America/Lower_Princes, Europe/Vatican):
Undo recent changes, going back to the way these entries were done
in the last tz distribution. Only the Antarctica/South_Pole change
was retained.
* Makefile (TZDIR_BASENAME): New macro.
(TZDIR): Use it.
(other_two): Remove.
(right_posix, posix_right): Use a symbolic link if supported.
This saves about 2 megabytes' worth of installed files.
This continues in the series of moving entries to 'backward' if
they exist only because of obsolete tz rules about country codes.
This change does not affect any time stamps after 1970. Unlike
the previous change in this series, this one does affect time
stamps before 1970, but that's OK as pre-1970 time stamps are
out of scope for the tz database.
* antarctica (Antarctica/McMurdo, Antarctica/South_Pole):
Move to 'backward' and link to Pacific/Auckland.
* backward: Move links here from 'antarctica'.
* zone.tab: Coalesce McMurdo and South Pole, and add Scott Base
to the description.
* asia (Asia/Dili, Asia/Jakarta, Asia/Pontianak, Asia/Makassar)
(Asia/Jayapura): Use WIB/WITA/WIT rather than WIT/CIT/EIT, since
it's typical to use Indonesian-language abbreviations even when
writing in English. I surveyed the Internet and Google Books and
found several independent English-language sources using WIB/WITA/WIT,
whereas it seemed only tz-inspired sources used WIT/CIT/EIT.
Problem reported several times, by George Ziegler, Priyadi Iman
Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and Benny Lin;
see Lin's summary of the reports in
<http://mm.icann.org/pipermail/tz/2013-February/018609.html>.
This change does not affect time zone offsets, just alphabetic
abbreviations, such as tm_zone in the BSD-style struct tm.
(Asia/Jakarta): Use BMT, not JMT, for mean time from 1923 to 1932,
as Jakarta was called Batavia back then.
* backward: Move links here from other files, if the only reason
they existed was to fill out zone.tab. Zones are now allowed to
cross national borders, so a zone now need not exist merely
because there's a national border. Sort the list consistently.
None of this changes any time stamp in the database.
* checktab.awk: Don't require that zone.tab's column 3 be unique.
* europe (Europe/Jersey, Europe/Guernsey, Europe/Isle_of_Man)
(Europe/Mariehamn, Europe/Busingen, Europe/Vatican, Europe/San_Marino)
(Arctic/Longyearbyen, Europe/Ljubljana, Europe/Podgorica)
(Europe/Sarajevo, Europe/Skopje, Europe/Zagreb, Europe/Bratislava):
* northamerica (America/St_Barthelemy, America/Marigot):
* southamerica (America/Lower_Princes, America/Kralendijk):
Move links to 'backward'.
* zone.tab: Give more details about how different rows can have
duplicate column 1 or column 3. For each link moved to 'backward',
change column 3 to be the non-backward name.
* date.1: Document -r.
* date.c (main, usage): Support -r.
(main, reset): Remove EBUG code.
(display): New argument NOW. Do not exit; that's now the
caller's responsibility. All callers changed.
(display, timeout, convert, checkfinal, iffy):
Don't assume that localtime and gmtime succeed.
This prevents a core dump for, e.g., 'date -r 0xffffffffffffffff'.
* private.h: Include float.h.
(strtoimax): New macro, for pre-C99 systems that lack strtoimax.
(time_t_min, time_t_max): New constants, from zdump, with
different names to avoid a clash when zdump.c includes private.h.
(tmcomp): Don't mess up when atmp->tm_year - btmp->tm_year overflows.
This can happen when mktime is invoked on a struct tm with tm_year
equal to INT_MIN.
See the thread starting with Clive D.W. Feather's comments in
<http://mm.icann.org/pipermail/tz/2013-August/019496.html>.
* localtime.c (truncate_time): Don't bother with uintmax_t,
as using it doesn't help on any known platform.
* private.h (UINTMAX_MAX): Remove.
Problem reported by Alois Treindl in
<http://mm.icann.org/pipermail/tz/2013-August/019493.html>.
* localtime.c (truncate_time): New function.
(localsub): Use it to avoid undefined behavior on integer overflow.
* private.h (INTMAX_MAX, INTMAX_MIN, UINTMAX_MAX):
New macros, for older platforms that lack them.
* localtime.c (offtime, timeoff, gtime): Revert change to ABI, by
going back to 'long' instead of 'int_fast32_t' for types accepted
and returned by extern functions. Reported by Christos Zoulas in
<http://mm.icann.org/pipermail/tz/2013-July/019488.html>.
* tz-link.htm: Add commentary section. Update URLs and titles.
Add links to Firefox OS, Bill Seymour's intro, Jon Udell's appreciation,
W3C's "Working with Time Zones".
