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Merge tzcode-2024b

Release 2024b - 2024-09-04 12:27:47 -0700

  Changes to code

    localtime.c now always uses a TZif file's time type 0 to handle
    timestamps before the file's first transition.  Formerly,
    localtime.c sometimes inferred a different time type, in order to
    handle problematic data generated by zic 2018e or earlier.  As it
    is now safe to assume more recent versions of zic, there is no
    longer a pressing need to fail to conform RFC 8536 section 3.2,
    which requires using time type 0 in this situation.  This change
    does not affect behavior when reading TZif files generated by zic
    2018f and later.

    POSIX.1-2024 removes asctime_r and ctime_r and does not let
    libraries define them, so remove them except when needed to
    conform to earlier POSIX.  These functions are dangerous as they
    can overrun user buffers.  If you still need them, add
    -DSUPPORT_POSIX2008 to CFLAGS.

    The SUPPORT_C89 option now defaults to 1 instead of 0, fixing a
    POSIX-conformance bug introduced in 2023a.

    tzselect now supports POSIX.1-2024 proleptic TZ strings.  Also, it
    assumes POSIX.2-1992 or later, as practical porting targets now
    all support that, and it uses some features from POSIX.1-2024 if
    available.

  Changes to build procedure

    'make check' no longer requires curl and Internet access.

    The build procedure now assumes POSIX.2-1992 or later, to simplify
    maintenance.  To build on Solaris 10, the only extant system still
    defaulting to pre-POSIX, prepend /usr/xpg4/bin to PATH.

  Changes to documentation

    The documentation now reflects POSIX.1-2024.

  Changes to commentary

    Commentary about historical transitions in Portugal and her former
    colonies has been expanded with links to many relevant legislation.
    (Thanks to Tim Parenti.)

Sync with tzcode2024a:
Release 2024a - 2024-02-01 09:28:56 -0800

  Changes to code

    The FROM and TO columns of Rule lines can no longer be "minimum"
    or an abbreviation of "minimum", because TZif files do not support
    DST rules that extend into the indefinite past - although these
    rules were supported when TZif files had only 32-bit data, this
    stopped working when 64-bit TZif files were introduced in 1995.
    This should not be a problem for realistic data, since DST was
    first used in the 20th century.  As a transition aid, FROM columns
    like "minimum" are now diagnosed and then treated as if they were
    the year 1900; this should suffice for TZif files on old systems
    with only 32-bit time_t, and it is more compatible with bugs in
    2023c-and-earlier localtime.c.  (Problem reported by Yoshito
    Umaoka.)

    localtime and related functions no longer mishandle some
    timestamps that occur about 400 years after a switch to a time
    zone with a DST schedule.  In 2023d data this problem was visible
    for some timestamps in November 2422, November 2822, etc. in
    America/Ciudad_Juarez.  (Problem reported by Gilmore Davidson.)

    strftime %s now uses tm_gmtoff if available.  (Problem and draft
    patch reported by Dag-Erling Smørgrav.)

  Changes to build procedure

    The leap-seconds.list file is now copied from the IERS instead of
    from its downstream counterpart at NIST, as the IERS version is
    now in the public domain too and tends to be more up-to-date.
    (Thanks to Martin Burnicki for liaisoning with the IERS.)

  Changes to documentation

    The strftime man page documents which struct tm members affect
    which conversion specs, and that tzset is called.  (Problems
    reported by Robert Elz and Steve Summit.)

Catch up with all the lint warnings since exit on warning was disabled.
Disable 'missing header declaration' and 'nested extern' warnings for now.

Import tzcode 2023d:

    localtime.c no longer mishandles TZif files that contain a single
    transition into a DST regime.  Previously, it incorrectly assumed
    DST was in effect before the transition too.  (Thanks to Alois
    Treindl for debugging help.)

    localtime.c's timeoff no longer collides with OpenBSD 7.4.

    The C code now uses _Generic only if __STDC_VERSION__ says the
    compiler is C11 or later.

    tzselect now optionally reads zonenow.tab, to simplify when
    configuring only for timestamps dated from now on.

    tzselect no longer creates temporary files.

    tzselect no longer mishandles the following:

      Spaces and most other special characters in BUGEMAIL, PACKAGE,
      TZDIR, and VERSION.

      TZ strings when using mawk 1.4.3, which mishandles regular
      expressions of the form /X{2,}/.

      ISO 6709 coordinates when using an awk that lacks the GNU
      extension of newlines in -v option-arguments.

      Non UTF-8 locales when using an iconv command that lacks the GNU
      //TRANSLIT extension.

    zic no longer mishandles data for Palestine after the year 2075.
    Previously, it incorrectly omitted post-2075 transitions that are
    predicted for just before and just after Ramadan.  (Thanks to Ken
    Murchison for debugging help.)

    zic now works again on Linux 2.6.16 and 2.6.17 (2006).

Update tzcode from 2022g to 2023c:

Release 2023c - 2023-03-28 12:42:14 -0700

Release 2023b - 2023-03-23 19:50:38 -0700

Release 2023a - 2023-03-22 12:39:33 -0700

  Changes to code

    You can now tell tzselect local time, to simplify later choices.
    Select the 'time' option in its first prompt.

    You can now compile with -DTZNAME_MAXIMUM=N to limit time zone
    abbreviations to N bytes (default 255).  The reference runtime
    library now rejects POSIX-style TZ strings that contain longer
    abbreviations, treating them as UTC.  Previously the limit was
    platform dependent and abbreviations were silently truncated to
    16 bytes even when the limit was greater than 16.

    The code by default is now designed for C99 or later.  To build in
    a C89 environment, compile with -DPORT_TO_C89.  To support C89
    callers of the tzcode library, compile with -DSUPPORT_C89.  The
    two new macros are transitional aids planned to be removed in a
    future version, when C99 or later will be required.

    The code now builds again on pre-C99 platforms, if you compile
    with -DPORT_TO_C89.  This fixes a bug introduced in 2022f.

    On C23-compatible platforms tzcode no longer uses syntax like
    'static [[noreturn]] void usage(void);'.  Instead, it uses
    '[[noreturn]] static void usage(void);' as strict C23 requires.
    (Problem reported by Houge Langley.)

    The code's functions now constrain their arguments with the C
    'restrict' keyword consistently with their documentation.
    This may allow future optimizations.

    zdump again builds standalone with ckdadd and without setenv,
    fixing a bug introduced in 2022g.  (Problem reported by panic.)

    leapseconds.awk can now process a leap seconds file that never
    expires; this might be useful if leap seconds are discontinued.

  Changes to commentary

    tz-link.html has a new section "Coordinating with governments and
    distributors".  (Thanks to Neil Fuller for some of the text.)

    To improve tzselect diagnostics, zone1970.tab's comments column is
    now limited to countries that have multiple timezones.

    Note that leap seconds are planned to be discontinued by 2035.

Pull up following revision(s) (requested by riastradh in ticket #242):

	lib/libc/time/localtime.c: revision 1.137
	lib/libc/time/zdump.c: revision 1.61
	lib/libc/time/NEWS: revision 1.41
	lib/libc/time/zic.c: revision 1.88
	lib/libc/time/zic.c: revision 1.89
	lib/libc/time/private.h: revision 1.65

Apply 9cfe9507fcc22cd4a0c4da486ea1c7f0de6b075f for C23 attribute compliance.
Requested by Jan-Benedict Glaw.

put attributes first for c23 compliance.

Apply 9cfe9507fcc22cd4a0c4da486ea1c7f0de6b075f for C23 attribute compliance.
Requested by Jan-Benedict Glaw.

Merge in 2022g:

    Although tzcode still works with C89, bugs found in recent routine
    maintenance indicate that bitrot has set in and that in practice
    C89 is no longer used to build tzcode.  As it is a maintenance
    burden, support for C89 is planned to be removed soon.  Instead,
    please use compilers compatible with C99, C11, C17, or C23.

    timegm, which tzcode implemented in 1989, will finally be
    standardized 34 years later as part of C23, so timegm is now
    supported even if STD_INSPIRED is not defined.

    Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone.
    (Problem reported by Đoàn Trần Công Danh.)

    Fix bug in zic on hosts where malloc(0) yields NULL on success.
    (Problem reported by Tim McBrayer for AIX 6.1.)

    Fix zic configuration to avoid linkage failures on some platforms.
    (Problems reported by Gilmore Davidson and Igor Ivanov.)

    Work around MS-Windows nmake incompatibility with POSIX.
    (Problem reported by Manuela Friedrich.)

    Port mktime and strftime to debugging platforms where accessing
    uninitialized data has undefined behavior (strftime problem
    reported by Robert Elz).

    Check more carefully for unlikely integer overflows, preferring
    C23 <stdckdint.h> to overflow checking by hand, as the latter has
    had obscure bugs.

Simply set HAVE_GETRANDOM to false on __APPLE__.

Addresses PR 57083.

PR/57083: Jiaxun Yang: Fix build on MacOS/X which has <sys/random.h> but no
getrandom(3).

Update to tzcode2022f

  Changes to code

    zic now supports links to links regardless of input line order.
    For example, if Australia/Sydney is a Zone, the lines
      Link Australia/Canberra Australia/ACT
      Link Australia/Sydney Australia/Canberra
    now work correctly, even though the shell commands
      ln Australia/Canberra Australia/ACT
      ln Australia/Sydney Australia/Canberra
    would fail because the first command attempts to use a link
    Australia/Canberra that does not exist until after the second
    command is executed.  Previously, zic had unspecified behavior if
    a Link line's target was another link, and zic often misbehaved if
    a Link line's target was a later Link line.

    Fix line number in zic's diagnostic for a link to a link.

    Fix a bug that caused localtime to mishandle timestamps starting
    in the year 2438 when reading data generated by 'zic -b fat' when
    distant-future DST transitions occur at times given in standard
    time or in UT, not the usual case of local time.  This occurs when
    the corresponding .zi Rule lines specify DST transitions with TO
    columns of 'max' and AT columns that end in 's' or 'u'.  The
    number 2438 comes from the 32-bit limit in the year 2038, plus the
    400-year Gregorian cycle.  (Problem reported by Bradley White.)

    On glibc 2.34 and later, which optionally supports 64-bit time_t
    on platforms like x86 where time_t was traditionally 32 bits,
    default time_t to 64 instead of 32 bits.  This lets functions like
    localtime support timestamps after the year 2038, and fixes
    year-2038 problems in zic when accessing files dated after 2038.
    To continue to limit time_t to 32 bits on these platforms, use
    "make CFLAGS='-D_TIME_BITS=32'".

    In C code, do not enable large-file support on platforms like AIX
    and macOS that no longer need it now that tzcode does not use
    off_t or related functions like 'stat'.  Large-file support is
    still enabled by default on GNU/Linux, as it is needed for 64-bit
    time_t support.

    In C code, prefer C23 keywords to pre-C23 macros for alignof,
    bool, false, and true.  Also, use the following C23 features if
    available: __has_include, unreachable.

    zic no longer works around Qt bug 53071, as the relevant Qt
    releases have been out of support since 2019.  This change affects
    only fat TZif files, as thin files never had the workaround.

    zdump no longer modifies the environ vector when compiled on
    platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
    This avoid undefined behavior on POSIX platforms.

Welcome to tzcode-2022c

Work around a bug in onetrueawk that broke commands like
'make traditional_tarballs' on FreeBSD, macOS, etc.
(Problem reported by Deborah Goldsmith.)

Add code to tzselect that uses experimental structured comments in
zone1970.tab to clarify whether Zones like Africa/Abidjan and
Europe/Istanbul cross continent or ocean boundaries.
(Inspired by a problem reported by Peter Krefting.)

Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
directory /a/b already exists.

Remove zoneinfo2tdf.pl, as it was unused and triggered false
malware alarms on some email servers.

Welcome to 2022b:

zic has a new option '-R @N' to output explicit transitions < N.
(Need suggested by Almaz Mingaleev.)

'zic -r @N' no longer outputs bad data when N < first transition.
(Problem introduced in 2021d and reported by Peter Krefting.)

zic now checks its input for NUL bytes and unterminated lines, and
now supports input line lengths up to 2048 (not 512) bytes.

gmtime and related code now use the abbreviation "UTC" not "GMT".
POSIX is being revised to require this.

When tzset and related functions set vestigial static variables
like tzname, they now prefer specified timestamps to unspecified ones.
(Problem reported by Almaz Mingaleev.)

zic no longer complains "can't determine time zone abbreviation to
use just after until time" when a transition to a new standard
time occurs simultanously with the first DST fallback transition.

welcome to tzcode-2022a

  Changes to code

    Fix bug when mktime gets confused by truncated TZif files with
    unspecified local time.  (Problem reported by Almaz Mingaleev.)

    Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
    (Problem reported by Christos Zoulas.)

    When reading a version 2 or later TZif file, the TZif reader now
    validates the version 1 header and data block only enough to skip
    over them, as recommended by RFC 8536 section 4.  Also, the TZif
    reader no longer mistakenly attempts to parse a version 1 TZIf
    file header as a TZ string.

    zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
    when local time and UT cannot be determined for a timestamp.

Change to code and documentation from 2021a -> 2021e

Release 2021e - 2021-10-21 18:41:00 -0700

  Changes to code

    none


Release 2021d - 2021-10-15 13:48:18 -0700

  Changes to code

    'zic -r' now uses "-00" time zone abbreviations for intervals
    with UT offsets that are unspecified due to -r truncation.
    This implements a change in draft Internet RFC 8536bis.


Release 2021c - 2021-10-01 14:21:49 -0700

  Changes to code

    Fix a bug in 'zic -b fat' that caused old timestamps to be
    mishandled in 32-bit-only readers (problem reported by Daniel
    Fischer).

  Changes to documentation

    Distribute the SECURITY file (problem reported by Andreas Radke).


Release 2021b - 2021-09-24 16:23:00 -0700

  Changes to maintenance procedure

    The new file SECURITY covers how to report security-related bugs.

    Several backward-compatibility links have been moved to the
    'backward' file.  These links, which range from Africa/Addis_Ababa
    to Pacific/Saipan, are only for compatibility with now-obsolete
    guidelines suggesting an entry for every ISO 3166 code.
    The intercontinental convenience links Asia/Istanbul and
    Europe/Nicosia have also been moved to 'backward'.

  Changes to code

    zic now creates each output file or link atomically,
    possibly by creating a temporary file and then renaming it.
    This avoids races where a TZ setting would temporarily stop
    working while zic was installing a replacement file or link.

    zic -L no longer omits the POSIX TZ string in its output.
    Starting with 2020a, zic -L truncated its output according to the
    "Expires" directive or "#expires" comment in the leapseconds file.
    The resulting TZif files omitted daylight saving transitions after
    the leap second table expired, which led to far less-accurate
    predictions of times after the expiry.  Although future timestamps
    cannot be converted accurately in the presence of leap seconds, it
    is more accurate to convert near-future timestamps with a few
    seconds error than with an hour error, so zic -L no longer
    truncates output in this way.

    Instead, when zic -L is given the "Expires" directive, it now
    outputs the expiration by appending a no-change entry to the leap
    second table.  Although this should work well with most TZif
    readers, it does not conform to Internet RFC 8536 and some pickier
    clients (including tzdb 2017c through 2021a) reject it, so
    "Expires" directives are currently disabled by default.  To enable
    them, set the EXPIRES_LINE Makefile variable.  If a TZif file uses
    this new feature it is marked with a new TZif version number 4,
    a format intended to be documented in a successor to RFC 8536.

    zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
    that omits leap second information for the range LO..B when LO
    falls between two leap seconds A and B.  Instead, it generates a
    TZif version 4 file that represents the previously-missing
    information.

    The TZif reader now allows the leap second table to begin with a
    correction other than -1 or +1, and to contain adjacent
    transitions with equal corrections.  This supports TZif version 4.

    The TZif reader now lets leap seconds occur less than 28 days
    apart.  This supports possible future TZif extensions.

    Fix bug that caused 'localtime' etc. to crash when TZ was
    set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
    not conform to POSIX but does conform to Internet RFC 8536.

    Fix another bug that caused 'localtime' etc. to crash when TZ was
    set to a POSIX-conforming but unusual TZ string like
    "EST5EDT4,0/0,J365/0", where almost all the year is DST.

    Fix yet another bug that caused 'localtime' etc. to mishandle slim
    TZif files containing leap seconds after the last explicit
    transition in the table, or when handling far-future timestamps
    in slim TZif files lacking leap seconds.

    Fix localtime misbehavior involving positive leap seconds.
    This change affects only behavior for "right" system time,
    which contains leap seconds, and only if the UT offset is
    not a multiple of 60 seconds when a positive leap second occurs.
    (No such timezone exists in tzdb, luckily.)  Without the fix,
    the timestamp was ambiguous during a positive leap second.
    With the fix, any seconds occurring after a positive leap second
    and within the same localtime minute are counted through 60, not
    through 59; their UT offset (tm_gmtoff) is the same as before.
    Here is how the fix affects timestamps in a timezone with UT
    offset +01:23:45 (5025 seconds) and with a positive leap second at
    1972-06-30 23:59:60 UTC (78796800):

	time_t    without the fix      with the fix
	78796800  1972-07-01 01:23:45  1972-07-01 01:23:45 (leap second)
	78796801  1972-07-01 01:23:45  1972-07-01 01:23:46
	...
	78796815  1972-07-01 01:23:59  1972-07-01 01:23:60
	78796816  1972-07-01 01:24:00  1972-07-01 01:24:00

    Fix an unlikely bug that caused 'localtime' etc. to misbehave if
    civil time changes a few seconds before time_t wraps around, when
    leap seconds are enabled.

    Fix bug in zic -r; in some cases, the dummy time type after the
    last time transition disagreed with the TZ string, contrary to
    Internet RFC 8563 section 3.3.

    Fix a bug with 'zic -r @X' when X is a negative leap second that
    has a nonnegative correction.  Without the fix, the output file
    was truncated so that X appeared to be a positive leap second.
    Fix a similar, even-less-likely bug when truncating at a positive
    leap second that has a nonpositive correction.

    zic -r now reports an error if given rolling leap seconds, as this
    usage has never generally worked and is evidently unused.

    zic now generates a POSIX-conforming TZ string for TZif files
    where all-year DST is predicted for the indefinite future.
    For example, for all-year Eastern Daylight Time, zic now generates
    "XXX3EDT4,0/0,J365/23" where it previously generated
    "EST5EDT,0/0,J365/25" or "".  (Thanks to Michael Deckers for
    noting the possibility of POSIX conformance.)

    zic.c no longer requires sys/wait.h (thanks to spazmodius for
    noting it wasn't needed).

    When reading slim TZif files, zdump no longer mishandles leap
    seconds on the rare platforms where time_t counts leap seconds,
    fixing a bug introduced in 2014g.

    zdump -v now outputs timestamps at boundaries of what localtime
    and gmtime can represent, instead of the less-useful timestamps
    one day after the minimum and one day before the maximum.
    (Thanks to Arthur David Olson for prototype code, and to Manuela
    Friedrich for debugging help.)

    zdump's -c and -t options are now consistently inclusive for the
    lower time bound and exclusive for the upper.  Formerly they were
    inconsistent.  (Confusion noted by Martin Burnicki.)

  Changes to build procedure

    You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
    non-POSIX hosts where malloc doesn't set errno.
    (Problem reported by Jan Engelhardt.)

  Changes to documentation

    tzfile.5 better matches a draft successor to RFC 8536
    <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.

Bring in 2020a

Sync with HEAD

deal with zic that's not part of libc.

Make strftime_{l,z} re-entrant and always require a non-NULL timezone to be
passed in so that we can use the current timezone in all evaluations (mktime
tzgetname). Reported by Hamilton Slye.

Sync with head

Update to 2018f:

  Changes to code

    zic now always generates TZif files where time type 0 is used for
    timestamps before the first transition.  This simplifies the
    reading of TZif files and should not affect behavior of existing
    TZif readers because the same set of time types is used; only
    their internal indexes may have changed.  This affects only the
    legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
    EET, which previously used nonzero types for these timestamps.

    Because of the type 0 change, zic no longer outputs a dummy
    transition at time -2**59 (before the Big Bang), as clients should
    no longer need this to handle historical timestamps correctly.
    This reverts a change introduced in 2013d and shrinks most TZif
    files by a few bytes.

    zic now supports negative time-of-day in Rule and Leap lines, e.g.,
    "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
    occurs at 18:00 on the Saturday before the last Sunday in April.
    This behavior was documented in 2018a but the code did not
    entirely match the documentation.

    localtime.c no longer requires at least one time type in TZif
    files that lack transitions or have a POSIX-style TZ string.  This
    future-proofs the code against possible future extensions to the
    format that would allow TZif files with POSIX-style TZ strings and
    without transitions or time types.

    A read-access subscript error in localtime.c has been fixed.
    It could occur only in TZif files with timecnt == 0, something that
    does not happen in practice now but could happen in future versions.

    localtime.c no longer ignores TZif POSIX-style TZ strings that
    specify only standard time.  Instead, these TZ strings now
    override the default time type for timestamps after the last
    transition (or for all time stamps if there are no transitions),
    just as DST strings specifying DST have always done.

    leapseconds.awk now outputs "#updated" and "#expires" comments,
    and supports leap seconds at the ends of months other than June
    and December.  (Inspired by suggestions from Chris Woodbury.)

  Changes to documentation

    New restrictions: A Rule name must start with a character that
    is neither an ASCII digit nor "-" nor "+", and an unquoted name
    should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
    The latter restriction makes room for future extensions (a
    possibility noted by Tom Lane).

    tzfile.5 now documents what time types apply before the first and
    after the last transition, if any.

    Documentation now uses the spelling "timezone" for a TZ setting
    that determines timestamp history, and "time zone" for a
    geographic region currently sharing the same standard time.

    The name "TZif" is now used for the tz binary data format.

    tz-link.htm now mentions the A0 TimeZone Migration utilities.
    (Thanks to Aldrin Martoq for the link.)

Sync with HEAD

Merge 2018e

  Changes to code

    zic now accepts subsecond precision in expressions like
    00:19:32.13, which is approximately the legal time of the
    Netherlands from 1835 to 1937.  However, because it is
    questionable whether the few recorded uses of non-integer offsets
    had subsecond precision in practice, there are no plans for tzdata
    to use this feature.  (Thanks to Steve Allen for pointing out
    the limitations of historical data in this area.)

    The code is a bit more portable to MS-Windows.  Installers can
    compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
    reserve identifiers like 'localtime'.  (Thanks to Manuela
    Friedrich).

  Changes to documentation and commentary

    theory.html now outlines tzdb's extensions to POSIX's model for
    civil time, and has a section "POSIX features no longer needed"
    that lists POSIX API components that are now vestigial.
    (From suggestions by Steve Summit.)  It also better distinguishes
    time zones from tz regions.  (From a suggestion by Guy Harris.)

    Commentary is now more consistent about using the phrase "daylight
    saving time", to match the C name tm_isdst.  Daylight saving time
    need not occur in summer, and need not have a positive offset from
    standard time.

    Commentary about historical transitions in Uruguay has been expanded
    with links to many relevant legal documents.
    (Thanks to Tim Parenti.)

    Commentary now uses some non-ASCII characters with Unicode value
    less than U+0100, as they can be useful and should work even with
    older editors such as XEmacs.

Welcome to 2017c:

    zic and the reference runtime now reject multiple leap seconds
    within 28 days of each other, or leap seconds before the Epoch.
    As a result, support for double leap seconds, which was
    obsolescent and undocumented, has been removed.  Double leap
    seconds were an error in the C89 standard; they have never existed
    in civil timekeeping.  (Thanks to Robert Elz and Bradley White for
    noticing glitches in the code that uncovered this problem.)

    zic now warns about use of the obsolescent and undocumented -y
    option, and about use of the obsolescent TYPE field of Rule lines.

    zic now allows unambiguous abbreviations like "Sa" and "Su" for
    weekdays; formerly it rejected them due to a bug.  Conversely, zic
    no longer considers non-prefixes to be abbreviations; for example,
    it no longer accepts "lF" as an abbreviation for "lastFriday".
    Also, zic warns about the undocumented usage with a "last-"
    prefix, e.g., "last-Fri".

    Similarly, zic now accepts the unambiguous abbreviation "L" for
    "Link" in ordinary context and for "Leap" in leap-second context.
    Conversely, zic no longer accepts non-prefixes such as "La" as
    abbreviations for words like "Leap".

    zic no longer accepts leap second lines in ordinary input, or
    ordinary lines in leap second input.  Formerly, zic sometimes
    warned about this undocumented usage and handled it incorrectly.

    The new macro HAVE_TZNAME governs whether the tzname external
    variable is exported, instead of USG_COMPAT.  USG_COMPAT now
    governs only the external variables "timezone" and "daylight".
    This change is needed because the three variables are not in the
    same category: although POSIX requires tzname, it specifies the
    other two variables as optional.  Also, USG_COMPAT is now 1 or 0:
    if not defined, the code attempts to guess it from other macros.

    localtime.c and difftime.c no longer require stdio.h, and .c files
    other than zic.c no longer require sys/wait.h.

    zdump.c no longer assumes snprintf.  (Reported by Jonathan Leffler.)

    Calculation of time_t extrema works around a bug in GCC 4.8.4
    (Reported by Stan Shebs and Joseph Myers.)

    zic.c no longer mistranslates formats of line numbers in non-English
    locales.  (Problem reported by Benno Schulenberg.)

    Several minor changes have been made to the code to make it a
    bit easier to port to MS-Windows and Solaris.  (Thanks to Kees
    Dekker for reporting the problems.)

  Changes to documentation and commentary

    The two new files 'theory.html' and 'calendars' contain the
    contents of the removed file 'Theory'.  The goal is to document
    tzdb theory more accessibly.

    The zic man page now documents abbreviation rules.

    tz-link.htm now covers how to apply tzdata changes to clients.
    (Thanks to Jorge Fábregas for the AIX link.)  It also mentions MySQL.

    The leap-seconds.list URL has been updated to something that is
    more reliable for tzdb.  (Thanks to Tim Parenti and Brian Inglis.)

Sync with HEAD

Sync with HEAD

merge 2017a

Sync with netbsd-5

Sync with HEAD.  (Note that most of these changes are simply $NetBSD$
tag issues.)

Pull up following revision(s) (requested by kre in ticket #1323):
	lib/libc/time/private.h: patch
	lib/libc/time/zic.c: patch
Make zic properly parse newer tzdata files.

Pull up following revision(s) (requested by kre in ticket #1323):
	lib/libc/time/private.h: patch
	lib/libc/time/zic.c: patch
Make zic properly parse newer tzdata files.

lint knows about _Generic

tzcode2016i

Sync with HEAD

welcome to 2016h

merge tzcode2016g

Sync with 2016b

Release 2015g - 2015-10-01 00:39:51 -0700

  Changes affecting code

    localtime no longer mishandles America/Anchorage after 2037.
    (Thanks to Bradley White for reporting the bug.)

    The localtime module allows the variables 'timezone', 'daylight',
    and 'altzone' to be in common storage shared with other modules,
    and declares them in case the system <time.h> does not.
    (Problems reported by Kees Dekker.)

    On platforms with tm_zone, strftime.c now assumes it is not NULL.
    This simplifies the code and is consistent with zdump.c.
    (Problem reported by Christos Zoulas.)

  Changes affecting documentation

   The tzfile man page now documents that transition times denote the
   starts (not the ends) of the corresponding time periods.
   (Ambiguity reported by Bill Seymour.)

merge 2015f

don't define statics we don't need

merge tzcode2015e:

  Changes affecting code

    When displaying data, tzselect converts it to the current locale's
    encoding if the iconv command works.  (Problem reported by random832.)

    tzselect no longer mishandles Dominica, fixing a bug introduced
    in Release 2014f.  (Problem reported by Owen Leibman.)

    zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
    This fixes a bug introduced in Release 2014f.
    (Problem reported by Leonardo Chiquitto.)

welcome to tzcode 2015d (zic performance improvements and cleanups)

merge 2015b

Pull up the following revisions via patch, requested by apb in ticket #453:

doc/3RDPARTY                                   	 up to 1.1195
usr.sbin/zdump/Makefile                        	 up to 1.9
usr.sbin/zic/Makefile                          	 up to 1.15
lib/libc/time/Makefile                         	 up to 1.25
lib/libc/time/Makefile.inc                     	 up to 1.21
lib/libc/time/NEWS                             	 up to 1.8
lib/libc/time/README                           	 up to 1.9
lib/libc/time/Theory                           	 up to 1.16
lib/libc/time/asctime.c                        	 up to 1.20
lib/libc/time/checktab.awk                     	 up to 1.8
lib/libc/time/ctime.3                          	 up to 1.51
lib/libc/time/getdate.c                        	 up to 1.3
lib/libc/time/localtime.c                      	 up to 1.92
lib/libc/time/private.h                        	 up to 1.38
lib/libc/time/strftime.c                       	 up to 1.33
lib/libc/time/time2posix.3                     	 up to 1.19
lib/libc/time/tz-art.htm                       	 up to 1.8
lib/libc/time/tz-link.htm                      	 up to 1.20
lib/libc/time/tzfile.5                         	 up to 1.22
lib/libc/time/tzfile.h                         	 up to 1.16
lib/libc/time/tzselect.8                       	 up to 1.6
lib/libc/time/tzselect.ksh                     	 up to 1.12
lib/libc/time/tzset.3                          	 up to 1.31
lib/libc/time/zdump.8                          	 up to 1.14
lib/libc/time/zdump.c                          	 up to 1.40
lib/libc/time/zic.8                            	 up to 1.24
lib/libc/time/zic.c                            	 up to 1.52

Update tzcode from 2014e to 2014j.

merge 2014i

don't define functions we define in our own headers

Sync with tzcode2014h

Rebase to HEAD as of a few days ago.

Reduce diffs with upstream by automatically defining INITIALIZE as it was
intended.

merge tzcode2014f via patch

Rebase.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs.  ("Protocol error: too many arguments")

Welcome to 2014c
   Changes affecting code

     zic now generates transitions for minimum time values, eliminating
     guesswork when handling low-valued time stamps.  (Thanks to Arthur
     David Olson.)

     Port to Cygwin sans glibc.  (Thanks to Arthur David Olson.)

   Changes affecting commentary and documentation

     Remove now-confusing comment about Jordan.  (Thanks to Oleksii
     Nochovnyi.)

update from tzcode 2013e to tzcode2013i
i:
    The compile-time flag NOSOLAR has been removed, as nowadays the
    benefit of slightly shrinking runtime table size is outweighed by the
    cost of disallowing potential future updates that exceed old limits.
h:
    Fix localtime overflow bugs with 32-bit unsigned time_t.

    zdump no longer assumes sscanf returns maximal values on overflow.
g:
    'zic' now runs on platforms that lack both hard links and symlinks.
    (Thanks to Theo Veenker for reporting the problem, for MinGW.)
    Also, fix some bugs on platforms that lack hard links but have symlinks.

    'zic -v' again warns that Asia/Tehran has no POSIX environment variable
    to predict the far future, fixing a bug introduced in 2013e.
f:
    The types of the global variables 'timezone' and 'altzone' (if present)
    have been changed back to 'long'.  This is required for 'timezone'
    by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
    These variables were originally 'long' in the tz code, but were
    mistakenly changed to 'time_t' in 1987; nobody reported the
    incompatibility until now.  The difference matters on x32, where
    'long' is 32 bits and 'time_t' is 64.  (Thanks to Elliott Hughes.)

time_t_{min,max} are only used in localtime.c

Welcome to tzcode 2013e:

  Changes affecting API

    The 'zic' command now outputs a dummy transition when far-future
    data can't be summarized using a TZ string, and uses a 402-year
    window rather than a 400-year window.  For the current data, this
    affects only the Asia/Tehran file.  It does not affect any of the
    time stamps that this file represents, so zdump outputs the same
    information as before.  (Thanks to Andrew Main (Zefram).)

    The 'date' command has a new '-r' option, which lets you specify
    the integer time to display, a la FreeBSD.

    The 'tzselect' command has two new options '-c' and '-n', which lets you
    select a zone based on latitude and longitude.

    The 'zic' command's '-v' option now warns about constructs that
    require the new version-3 binary file format.  (Thanks to Arthur
    David Olson for the suggestion.)

    Support for floating-point time_t has been removed.
    It was always dicey, and POSIX no longer requires it.
    (Thanks to Eric Blake for suggesting to the POSIX committee to
    remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
    Heninger, Arthur David Olson, and Alois Treindl, for reporting
    bugs and elucidating some of the corners of the old floating-point
    implementation.)

    The signatures of 'offtime', 'timeoff', and 'gtime' have been
    changed back to the old practice of using 'long' to represent UT
    offsets.  This had been inadvertently and mistakenly changed to
    'int_fast32_t'.  (Thanks to Christos Zoulos.)

    The code avoids undefined behavior on integer overflow in some
    more places, including gmtime, localtime, mktime and zdump.

  Changes affecting the zdump utility

    zdump now outputs "UT" when referring to Universal Time, not "UTC".
    "UTC" does not make sense for time stamps that predate the introduction
    of UTC, whereas "UT", a more-generic term, does.  (Thanks to Steve Allen
    for clarifying UT vs UTC.)

  Data changes affecting behavior of tzselect and similar programs

    Country code BQ is now called the more-common name "Caribbean Netherlands"
    rather than the more-official "Bonaire, St Eustatius & Saba".

    Remove from zone.tab the names America/Montreal, America/Shiprock,
    and Antarctica/South_Pole, as they are equivalent to existing
    same-country-code zones for post-1970 time stamps.  The data for
    these names are unchanged, so the names continue to work as before.

  Changes affecting code internals

    zic -c now runs way faster on 64-bit hosts when given large numbers.

    zic now uses vfprintf to avoid allocating and freeing some memory.

    tzselect now computes the list of continents from the data,
    rather than have it hard-coded.

    Minor changes pacify GCC 4.7.3 and GCC 4.8.1.

  Changes affecting the build procedure

    The 'leapseconds' file is now generated automatically from a
    new file 'leap-seconds.list', which is a copy of
    <ftp://time.nist.gov/pub/leap-seconds.list>.
    A new source file 'leapseconds.awk' implements this.
    The goal is simplification of the future maintenance of 'leapseconds'.

    When building the 'posix' or 'right' subdirectories, if the
    subdirectory would be a copy of the default subdirectory, it is
    now made a symbolic link if that is supported.  This saves about
    2 MB of file system space.

    The links America/Shiprock and Antarctica/South_Pole have been
    moved to the 'backward' file.  This affects only nondefault builds
    that omit 'backward'.

  Changes affecting documentation and commentary

    Changes to the 'tzfile' man page

      It now mentions that the binary file format may be extended in
      future versions by appending data.

      It now refers to the 'zdump' and 'zic' man pages.

    Changes to the 'zic' man page

      It lists conditions that elicit a warning with '-v'.

      It says that the behavior is unspecified when duplicate names
      are given, or if the source of one link is the target of another.

      Its examples are updated to match the latest data.

      The definition of white space has been clarified slightly.
      (Thanks to Michael Deckers.)

    Changes to the 'Theory' file

      There is a new section about the accuracy of the tz database,
      describing the many ways that errors can creep in, and
      explaining why so many of the pre-1970 time stamps are wrong or
      misleading (thanks to Steve Allen, Lester Caine, and Garrett
      Wollman for discussions that contributed to this).

      The 'Theory' file describes LMT better (this follows a
      suggestion by Guy Harris).

      It refers to the 2013 edition of POSIX rather than the 2004 edition.

      It's mentioned that excluding 'backward' should not affect the
      other data, and it suggests at least one zone.tab name per
      inhabited country (thanks to Stephen Colebourne).

      Some longstanding restrictions on names are documented, e.g.,
      'America/New_York' precludes 'America/New_York/Bronx'.

      It gives more reasons for the 1970 cutoff.

      It now mentions which time_t variants are supported, such as
      signed integer time_t.  (Thanks to Paul Goyette for reporting
      typos in an experimental version of this change.)

      (Thanks to Philip Newton for correcting typos in these changes.)

    Documentation and commentary is more careful to distinguish UT in
    general from UTC in particular.  (Thanks to Steve Allen.)

    Add a better source for the Zurich 1894 transition.
    (Thanks to Pierre-Yves Berger.)

    Update shapefile citations in tz-link.htm.  (Thanks to Guy Harris.)

sync with HEAD

welcome to 2013d

Resync to 2012-11-19 00:00:00 UTC

sync with head

stronger lint foo

apply 2012g via patch

merge 2012e

Import tzcode2009k.
- now understands 64bit time_t and 64bit data in timezone files.
- localtime(), gmtime(), asctime() and ctime() may now fail with
  a NULL result if time_t cannot be represented by struct tm.

import tzcode2009k

Merge tzcode2003e.

Import tzcode2003e.

Overhaul how `build.sh tools' are used:

    *	Rename "config.h" to "nbtool_config.h" and
	HAVE_CONFIG_H to HAVE_NBTOOL_CONFIG_H.
	This makes in more obvious in the source when we're using
	tools/compat/config.h versus "standard autoconf" config.h

    *	Consistently move the inclusion of nbtool_config.h to before
    	<sys/cdefs.h> so that the former can provide __RCSID() (et al),
    	and there's no need to protect those macros any more.

These changes should make it easier to "tool-ify" a program by adding:
	#if HAVE_NBTOOL_CONFIG_H
	#include "nbtool_config.h"
	#endif
to the top of the source files (for the general case).

Catch up to -current.

__STDC__ is always defined on NetBSD.

Pull in config.h when we're building zic as a host tool.
This makes zic compilable with Sun WorkShop C 5.0.

Catch up to -current.

Catch up to -current.

Merge tzcode2002b.

Import tzcode2002b.

#undef, not #undefine.

Merge strftime from tzcode2000g.

Merge tzcode2000g.

Import tzcode2000g.

#ifdef out duplicate declaration for unlink.

Pullup lib string format fixes [is].
See "cvs log" for explicit revision numbers per file, from sommerfeld.

Pull up revision 1.15 (requested by is):
  Format string cleanup.

Format string cleanup, by Bill Sommerfeld.

Pull up to last week's -current.

Merge tzcode1999h.

Import tzcode1999h.

Merge tzcode1998h.

Import tzcode1998H.

Merge tzcode1998f.

Import tzcode1998f.

Fix the approximation of log10(2.0) used in INT_STRLEN_MAXIMUM; this resulted
in a fair amount of space wasted in the static result buffer used in
asctime().  Noticed by Randy Thelen <rthelen@netapp.com> on tz@elsie.

sync with tzcode1997g

import tzcode1997g

Fix RCSID's

Sync with tzcode1997e

import tzcode1997e

set HAVE_STRERROR

sync with tzcode96l

import tzcode96l

sync with tzcode96c

import tzcode96c

sync with tzcode96a

import tzcode96a

Added some #defines for NetBSD's defaults.

Add NetBSD Id's.

file private.h was added on branch ivory_soap on 1995-03-09 23:41:20 +0000

Add NetBSD Id's.

New time and date code from ADO

Initial revision