- tz - lists.iana.org

Namibia to change time zone/go permanent DST
by Steffen Thorsen Aug. 10, 2017

Aug. 10, 2017

Namibia is going to change their time zone to what is now their DST: https://www.newera.com.na/2017/02/23/namibias-winter-time-might-be-repealed/ This video is from the government decision: https://www.nbc.na/news/na-passes-namibia-time-bill-repealing-1994-namibia-… We have made the assumption so far that they will change their time zone at the same time they would normally start DST, the first Sunday in September: https://www.timeanddate.com/news/time/namibia-new-time-zone.html Best regards, Steffen

4 6

Israel POSIX timezone string error on release 2017b?
by André Domingos Brízido Aug. 8, 2017

Aug. 8, 2017

Hello According to the Linux manual (http://man7.org/linux/man-pages/man5/tzfile.5.html) the last line of the time zone database may contain the POSIX timezone string, which is the case of the files generated by following the instructions in https://www.iana.org/time-zones/repository/tz-link.html I've downloaded the latest release (2017b) and I obtain the following POSIX string for Israel: [/usr/share/zoneinfo]# tail -n 1 Israel IST-2IDT,M3.4.4/26,M10.5.0 But if I understood correctly, the POSIX specification (http://pubs.opengroup.org/onlinepubs/9699919799/) states that the value '26' is out of range. It should be between zero and 24. My linux system does not display the correct timezone if I use the string 'IST-2IDT,M3.4.4/26,M10.5.0' as the contents of /etc/TZ. Best regards Andre Brizido

4 6

[PROPOSED] Improve tzfile.5 formatting and clarity
by Paul Eggert Aug. 7, 2017

Aug. 7, 2017

* tzfile.5: Break out field descriptions into bulleted lists, to make them easier to follow. This does not change the technical content of the spec, just its presentation. --- tzfile.5 | 77 ++++++++++++++++++++++++++++++++++++++++------------------------ 1 file changed, 48 insertions(+), 29 deletions(-) diff --git a/tzfile.5 b/tzfile.5 index 52c5301..b7dc828 100644 --- a/tzfile.5 +++ b/tzfile.5 @@ -10,17 +10,29 @@ tzfile \- time zone information \\$3\*(lq\\$1\*(rq\\$2 .. The time zone information files used by -.IR tzset (3) -begin with the magic characters "TZif" to identify them as -time zone information files, -followed by a character identifying the version of the file's format -(as of 2013, either an ASCII NUL, or '2', or '3') -followed by fifteen bytes containing zeroes reserved for future use, -followed by six four-byte integer values +.BR tzset (3) +are typically found under a directory with a name like +.IR /usr/share/zoneinfo . +These files begin with a 44-byte header containing the following fields: +.IP * 2 +The magic four-byte ASCII sequence +.q "TZif" +identifies the file as a time zone information file. +.IP * +A byte identifying the version of the file's format +(as of 2017, either an ASCII NUL, or +.q "2", +or +.q "3" ). +.IP * +Fifteen bytes containing zeros reserved for future use. +.IP * +Six four-byte integer values written in a standard byte order (the high-order byte of the value is written first). These values are, in order: +.RS .TP .I tzh_ttisgmtcnt The number of UT/local indicators stored in the file. @@ -40,28 +52,30 @@ The number of local time types for which data entries are stored in the file (must not be zero). .TP .I tzh_charcnt -The number of characters of time zone abbreviation strings +The number of bytes of time zone abbreviation strings stored in the file. +.RE .PP -The above header is followed by +The above header is followed by the following fields, whose lengths +vary depend on the contents of the header: +.IP * 2 .I tzh_timecnt four-byte signed integer values sorted in ascending order. These values are written in standard byte order. Each is used as a transition time (as returned by -.IR time (2)) +.BR time (2)) at which the rules for computing local time change. -Next come +.IP * .I tzh_timecnt one-byte unsigned integer values; each one tells which of the different types of local time types described in the file is associated with the time period starting with the same-indexed transition time. -These values serve as indices into an array of -.I ttinfo -structures (with +These values serve as indices into the next field. +.IP * .I tzh_typecnt -entries) that appears next in the file; -these structures are defined as follows: +.I ttinfo +entries, each defined as follows: .in +.5i .sp .nf @@ -87,20 +101,19 @@ gives the number of seconds to be added to UT, tells whether .I tm_isdst should be set by -.I localtime (3) +.BR localtime (3) and .I tt_abbrind -serves as an index into the array of time zone abbreviation characters +serves as an index into the array of time zone abbreviation bytes that follow the .I ttinfo structure(s) in the file. -.PP -Then there are +.IP * .I tzh_leapcnt pairs of four-byte values, written in standard byte order; the first value of each pair gives the nonnegative time (as returned by -.IR time(2)) +.BR time (2)) at which a leap second occurs; the second gives the .I total @@ -109,16 +122,14 @@ starting at the given time. The pairs of values are sorted in ascending order by time. Each transition is for one leap second, either positive or negative; transitions always separated by at least 28 days minus 1 second. -.PP -Then there are +.IP * .I tzh_ttisstdcnt standard/wall indicators, each stored as a one-byte value; they tell whether the transition times associated with local time types were specified as standard time or wall clock time, and are used when a time zone file is used in handling POSIX-style time zone environment variables. -.PP -Finally there are +.IP * .I tzh_ttisgmtcnt UT/local indicators, each stored as a one-byte value; they tell whether the transition times associated with local time types @@ -126,7 +137,9 @@ 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 -.I Localtime +The +.BR localtime (3) +function uses the first standard-time .I ttinfo structure in the file @@ -137,11 +150,12 @@ if either .I tzh_timecnt is zero or the time argument is less than the first transition time recorded in the file. -.PP +.SS Version 2 format For version-2-format time zone files, the above header and data are followed by a second header and data, identical in format except that eight bytes are used for each transition time or leap second time. +(Leap second counts remain four bytes.) After the second header and data comes a newline-enclosed, POSIX-TZ-environment-variable-style string for use in handling instants after the last transition time stored in the file @@ -154,7 +168,7 @@ then if a last transition time is in July, the transition's local time type must specify a daylight-saving time abbreviated .q "WEST" that is one hour east of UT. -.PP +.SS Version 3 format For version-3-format time zone files, the POSIX-TZ-style string may use two minor extensions to the POSIX TZ format, as described in .IR newtzset (3). @@ -166,6 +180,11 @@ between daylight saving and standard time. .PP Future changes to the format may append more data. .SH SEE ALSO -newctime(3), newtzset(3), zdump(8), zic(8) +.BR time (2), +.BR localtime (3), +.BR tzset (3), +.BR tzselect (8), +.BR zdump (8), +.BR zic (8) .\" This file is in the public domain, so clarified as of .\" 1996-06-05 by Arthur David Olson. -- 2.7.4

2 3

[PROPOSED] Minor tz-link updates.
by Paul Eggert Aug. 1, 2017

Aug. 1, 2017

* tz-link.htm: Add Noda Time updater. Add a downloading header, and simplify text editor discussion. --- tz-link.htm | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/tz-link.htm b/tz-link.htm index 803727b..589c781 100644 --- a/tz-link.htm +++ b/tz-link.htm @@ -10,7 +10,7 @@ content="Sources for time zone and daylight saving time data"> <meta name="DC.Creator" content="Eggert, Paul"> <meta name="DC.Contributor" content="Olson, Arthur David"> -<meta name="DC.Date" content="2017-07-08"> +<meta name="DC.Date" content="2017-08-01"> <meta name="DC.Description" content="Sources of information about time zones and daylight saving time"> <meta name="DC.Identifier" @@ -105,6 +105,7 @@ Universal Time</a> (<abbr>UTC</abbr>). The database also records when daylight saving time was in use, along with some time zone abbreviations such as <abbr>EST</abbr> for Eastern Standard Time in the <abbr>US</abbr>.</p> +<h2 id="download">Downloading the <code><abbr>tz</abbr></code> database</h2> <p> The following <a href="https://en.wikipedia.org/wiki/Unix_shell">shell</a> commands download @@ -196,9 +197,10 @@ title="International Components for Unicode">ICU</abbr></a>, <a href="https://developer.ibm.com/javasdk/support/dst/jtzu/"><abbr>IBM</abbr></a> and <a href="http://www.oracle.com/technetwork/java/javase/tzupdater-readme-136440.html">Oracle</a> -Java, <a href="http://www.joda.org/joda-time/tz_update.html">Joda-Time</a>, +Java, <a href="http://www.joda.org/joda-time/tz_update.html">Joda-Time</a>, <a +href="https://dev.mysql.com/doc/refman/en/time-zone-support.html">MySQL</a>, and <a -href="https://dev.mysql.com/doc/refman/en/time-zone-support.html">MySQL</a>. +href="http://nodatime.org/userguide/tzdb">Noda Time</a> (see below). </p> <p>Sources for the <code><abbr>tz</abbr></code> database are <a href="https://en.wikipedia.org/wiki/UTF-8"><abbr @@ -209,14 +211,11 @@ title="linefeed">LF</abbr></a>, which can be modified by common text editors such as <a href="https://www.gnu.org/software/emacs/">GNU Emacs</a>, <a href="https://wiki.gnome.org/Apps/Gedit">gedit</a>, and -<a href="http://www.vim.org">vim</a>. One -editor has a package to simplify editing further:</p> -<ul> -<li><a href="https://packagecontrol.io/packages/zoneinfo">Sublime -zoneinfo</a> is a <a href="http://www.sublimetext.com">Sublime -Text</a> package for syntax highlighting <code><abbr>tz</abbr></code> -source files.</li> -</ul> +<a href="http://www.vim.org">vim</a>. The <a +href="http://www.sublimetext.com">Sublime Text</a> editor has +a <a href="https://packagecontrol.io/packages/zoneinfo">Sublime +zoneinfo</a> package to simplify editing further. +</p> <p> For further information about updates, please see <a href="https://tools.ietf.org/html/rfc6557">Procedures for -- 2.7.4

1 0

[PROPOSED] Detroit did not observe DST in 1967
by Paul Eggert July 27, 2017

July 27, 2017

* NEWS: Document this. * northamerica (Detroit): Remove bogus 1967 rules that were taken from Shanks. --- NEWS | 2 ++ northamerica | 15 +++++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/NEWS b/NEWS index 64d5c91..93633a5 100644 --- a/NEWS +++ b/NEWS @@ -4,6 +4,8 @@ Unreleased, experimental changes Changes to past time stamps + Detroit did not observe DST in 1967. + Use railway time for Asia/Kolkata before 1941, by switching to Madras local time (UT +052110) in 1870, then to IST (UT +0530) in 1906. Also, treat 1941-2's +0630 as DST, like 1942-5. diff --git a/northamerica b/northamerica index 651681d..b42aeb4 100644 --- a/northamerica +++ b/northamerica @@ -1040,12 +1040,23 @@ Zone America/Kentucky/Monticello -5:39:24 - LMT 1883 Nov 18 12:20:36 # one hour in 1914." This change is not in Shanks. We have no more # info, so omit this for now. # +# From Paul Eggert (2017-07-26): +# Although Shanks says Detroit observed DST in 1967 from 06-14 00:01 +# until 10-29 00:01, I now see multiple reports that this is incorrect. +# For example, according to a 50-year anniversary report about the 1967 +# Detroit riots and a major-league doubleheader on 1967-07-23, "By the time +# the last fly ball of the doubleheader settled into the glove of leftfielder +# Lenny Green, it was after 7 p.m. Detroit did not observe daylight saving +# time, so light was already starting to fail. Twilight was made even deeper +# by billowing columns of smoke that ascended in an unbroken wall north of the +# ballpark." See: Dow B. Detroit '67: As violence unfolded, Tigers played two +# at home vs. Yankees. Detroit Free Press 2017-07-23. +# http://www.freep.com/story/sports/mlb/tigers/2017/07/23/detroit-tigers-1967… +# # Most of Michigan observed DST from 1973 on, but was a bit late in 1975. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER Rule Detroit 1948 only - Apr lastSun 2:00 1:00 D Rule Detroit 1948 only - Sep lastSun 2:00 0 S -Rule Detroit 1967 only - Jun 14 2:00 1:00 D -Rule Detroit 1967 only - Oct lastSun 2:00 0 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone America/Detroit -5:32:11 - LMT 1905 -6:00 - CST 1915 May 15 2:00 -- 2.13.3

1 0

Re: [tz] libc-2.25.90.pot
by Paul Eggert July 20, 2017

July 20, 2017

On 07/20/2017 07:57 AM, Siddhesh Poyarekar wrote: > Oh I meant PRIdLINENO, not PRIdMAX. I suppose using PRIdMAX directly > might work since gettext seems to recognize the other PRI* macros. Yes, PRIdMAX should work. The zic.c code uses the macro (as opposed to just %jd) to be portable to pre-C99 libraries. I installed the attached patch into the upstream tzdb sources; the zic.c part of it should work for glibc too. Thanks for reporting the problem.

1 0

[PROPOSED] Use more up-to-date citation for leap seconds
by Paul Eggert July 18, 2017

July 18, 2017

* leapseconds.awk: Cite Levine 2016 instead of Quinn 1991. --- leapseconds.awk | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/leapseconds.awk b/leapseconds.awk index 405ce3a..66eb64d 100644 --- a/leapseconds.awk +++ b/leapseconds.awk @@ -17,11 +17,9 @@ BEGIN { print "# The International Earth Rotation and Reference Systems Service" print "# periodically uses leap seconds to keep UTC to within 0.9 s of UT1" print "# (which measures the true angular orientation of the earth in space); see" - print "# Terry J Quinn, The BIPM and the accurate measure of time," - print "# Proc IEEE 79, 7 (July 1991), 894-905 <http://dx.doi.org/10.1109/5.84965>," - print "# reprinted in: Hackman C, Sullivan DB (eds), Time and frequency measurement," - print "# American Association of Physics Teachers (1996)," - print "# <http://tf.nist.gov/general/pdf/1168.pdf>, 75-86." + print "# Levine J. Coordinated Universal Time and the leap second." + print "# URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995" + print "# http://ieeexplore.ieee.org/document/7909995/" print "# There were no leap seconds before 1972, because the official mechanism" print "# accounting for the discrepancy between atomic time and the earth's rotation" print "# did not exist until the early 1970s." -- 2.7.4

3 3

Pedantic correction to Theory regarding size of time zone names
by Howard Hinnant July 16, 2017

July 16, 2017

Line 91 of Theory: https://github.com/eggert/tz/blob/master/Theory#L91 reads: > A file name component must not exceed 14 characters … I found one exception to this rule: The Link: Canada/East-Saskatchewan in backward. East-Saskatchewan is 17 characters. I recommend simply changing the 14 to 17. Howard

4 5

Unix time_t hits 1.5Gs early Friday UTC
by Brian Inglis July 14, 2017

July 14, 2017

Unix time_t will hit 1 500 000 000 at 2017 Jul 14 Fri 02:40:00+0000 which is Thursday evening in North America: $ for city in Vancouver Edmonton Regina Winnipeg Toronto Halifax St_Johns; do TZ=America/$city date -d@1500000000 +%c\ %Z; done 2017 Jul 13 Thu 19:40:00 PDT 2017 Jul 13 Thu 20:40:00 MDT 2017 Jul 13 Thu 20:40:00 CST 2017 Jul 13 Thu 21:40:00 CDT 2017 Jul 13 Thu 22:40:00 EDT 2017 Jul 13 Thu 23:40:00 ADT 2017 Jul 14 Fri 00:10:00 NDT and on some other time scales, which may not be aligned to UTC: $ gpstime.sh @1500000000 2017 Jul 14 Fri 02:40:00+0000 JD 2457948.611111 MJD 57948.111111 ToD 9599 NTP 3708988800 Unix 1500000000 TAI-UTC 37 TAI-GPS 19 GPS-UTC 18 GPS We 1957 Cy 1 Wn 933 Wa 165 ToW 441618 DoW 5 ToD 9618 As usual there will be some Europeans staying up late to celebrate and party. Unix time won't hit 1.5Gis until: $ gpstime.sh @`bc <<< 2^30*3/2` 2021 Jan 14 Thu 08:25:36+0000 JD 2459228.851111 MJD 59228.351111 ToD 30336 NTP 3819601536 Unix 1610612736 TAI-UTC 37 TAI-GPS 19 GPS-UTC 18 GPS We 2140 Cy 2 Wn 92 Wa 92 ToW 375954 DoW 4 ToD 30354 and it will be a while before it hits 2Gs: $ gpstime.sh @2000000000 2033 May 18 Wed 03:33:20+0000 JD 2463735.648148 MJD 63735.148148 ToD 12799 NTP 4208988800 Unix 2000000000 TAI-UTC 37 TAI-GPS 19 GPS-UTC 18 GPS We 2784 Cy 2 Wn 736 Wa 224 ToW 272018 DoW 3 ToD 12818 -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

3 2

Use GST abbreviation for Asia/Dubai, Asia/Muscat
by Mohamed Akram July 14, 2017

July 14, 2017

I noticed Asia/Dubai and Asia/Muscat currently use +04, but there is an existing abbreviation (GST - Gulf Standard Time).

3 3

Etc/GMT timezone offsets are inverted
by Pedro A. López-Valencia July 11, 2017

July 11, 2017

I just noticed that all GMT+- timezones are inverted so that GMT+5 is really GMT-5. This applies to all GMT-offset timezone definitions. -- https://about.me/palopezv

2 1

IERS Bulletin C54
by Michael Deckers July 11, 2017

July 11, 2017

The IERS has issued Bulletin C54 which assures that no leap second will occur near 2018-01-01. Interestingly, the issue date 2017-07-06 in the txt version at [https://datacenter.iers.org/eop/-/somos/5Rgv/getTX/16/bulletinc-054.txt] differs from the issue date 2017-07-09 in the xml version at [https://datacenter.iers.org/eop/-/somos/5Rgv/latestXL/16/bulletinc-054.txt/…] Michael Deckers. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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backzone/Europe/Guernsey
by Michael Deckers July 10, 2017

July 10, 2017

For the connoisseurs of olde time stamps: The "LMT location" for backzone/Europe/Guernsey is given as "49.27N -2.33E" -- seemingly in degrees and decimal fractions of degrees. But the point ( +49.27°, -2.33° ) = ( +49°16′12″, -002°19′48″ ) is in open waters about 15 km south of Guernsey and east of Sark in the Channel. The point ( +49°27′, -002°33′ ), however, is in St Peter Port on the island, so that arc minutes and not hundredths of degrees must be meant. This also agrees with zone.tab. Hence: -# LMT Location - 49.27N -2.33E - St.Peter Port +# LMT Location - 49°27′N -2°33′E - St.Peter Port -Zone Europe/Guernsey -0:09:19 - LMT 1913 Jun 18 +Zone Europe/Guernsey -0:10:12 - LMT 1913 Jun 18 Michael Deckers. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

3 3

Re: [tz] TZ & AIX
by Paul Eggert July 8, 2017

July 8, 2017

Jorge Fábregas wrote: > https://www.ibm.com/developerworks/aix/library/au-aix-olson-time-zone/index… Thanks for the heads-up. I installed the attached.

2 1

Orillia's 1912 DST pops up again in Toronto Star
by Paul Eggert July 8, 2017

July 8, 2017

Today's Toronto Star reports on the two-week daylight saving time interlude in Orillia, Ontario. Today's article doesn't mention the same newspaper's 1997-10-14 article on the same topic, and it's not clear what's new this time around. Still, the story is amusingly told. Proposed patch attached.

1 0

DST in the (odd) news
by Arthur David Olson July 7, 2017

July 7, 2017

"Alarm clock removed from family's home after 14 years of daily beeping" "Over the years, it beeped at 6.50pm or 7.50pm each day, depending on whether Daylight [Saving] Time was in place." https://www.theguardian.com/us-news/2017/jul/07/alarm-clock-wall-pennsylvan… @dashdashado

1 0

[PROPOSED] Avoid zic problems with errno == EOVERFLOW
by Paul Eggert June 26, 2017

June 26, 2017

Although this patch does not fix any bugs, it makes zic’s ‘stat’ calls less likely to fail unnecessarily with errno == EOVERFLOW, and this should be a bit faster in some cases. Problem reported by Nick Alcock in: https://sourceware.org/ml/libc-alpha/2017-06/msg01264.html * private.h (_FILE_OFFSET_BITS, _LARGE_FILES) (_DARWIN_USE_64_BIT_INODE): New macros. --- private.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/private.h b/private.h index f5e39b5..2e8415e 100644 --- a/private.h +++ b/private.h @@ -102,6 +102,16 @@ /* Enable strtoimax on pre-C99 Solaris 11. */ #define __EXTENSIONS__ 1 +/* To avoid having 'stat' fail unnecessarily with errno == EOVERFLOW, + enable large files on GNUish systems ... */ +#ifndef _FILE_OFFSET_BITS +# define _FILE_OFFSET_BITS 64 +#endif +/* ... and on AIX ... */ +#define _LARGE_FILES 1 +/* ... and enable large inode numbers on Mac OS X 10.5 and later. */ +#define _DARWIN_USE_64_BIT_INODE 1 + /* ** Nested includes */ -- 2.9.4

1 0

[PROPOSED] Port to GCC 4.8.4
by Paul Eggert June 16, 2017

June 16, 2017

Problem reported by Stan Shebs and Joseph Myers in: https://sourceware.org/ml/libc-alpha/2017-06/msg00741.html * NEWS, Makefile: Document this. * private.h (HAVE_GENERIC): New macro, so that we do not use _Generic with GCC 4.8. (TIME_T_MIN_NO_PADDING, TIME_T_MAX_NO_PADDING): New macros. (TIME_T_MIN, TIME_T_MAX): Rename from time_t_min and time_t_max, and turn them into macros so that problems are less likely to occur for subset uses like glibc where these macros are never expanded. All uses changed. Use new macros to work around GCC 4.8 bug. --- Makefile | 1 + NEWS | 3 +++ date.c | 2 +- localtime.c | 26 +++++++++++++------------- private.h | 60 ++++++++++++++++++++++++++++++++++++++++-------------------- 5 files changed, 58 insertions(+), 34 deletions(-) diff --git a/Makefile b/Makefile index 2b31f3f..347ece7 100644 --- a/Makefile +++ b/Makefile @@ -142,6 +142,7 @@ LDLIBS= # -DHAVE_DECL_ASCTIME_R=0 if <time.h> does not declare asctime_r # -DHAVE_DECL_ENVIRON if <unistd.h> declares 'environ' # -DHAVE_DIRECT_H if mkdir needs <direct.h> (MS-Windows) +# -DHAVE_GENERIC=0 if _Generic does not work # -DHAVE_GETTEXT if 'gettext' works (e.g., GNU/Linux, FreeBSD, Solaris) # -DHAVE_INCOMPATIBLE_CTIME_R if your system's time.h declares # ctime_r and asctime_r incompatibly with the POSIX standard diff --git a/NEWS b/NEWS index ca4fd8e..cfdd620 100644 --- a/NEWS +++ b/NEWS @@ -94,6 +94,9 @@ Unreleased, experimental changes 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.) + 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.) diff --git a/date.c b/date.c index b29e162..2cc533f 100644 --- a/date.c +++ b/date.c @@ -97,7 +97,7 @@ main(const int argc, char *argv[]) secs = strtoimax (optarg, &endarg, 0); if (*endarg || optarg == endarg) errno = EINVAL; - else if (! (time_t_min <= secs && secs <= time_t_max)) + else if (! (TIME_T_MIN <= secs && secs <= TIME_T_MAX)) errno = ERANGE; if (errno) { perror(optarg); diff --git a/localtime.c b/localtime.c index 8c944f3..2e1d621 100644 --- a/localtime.c +++ b/localtime.c @@ -464,17 +464,17 @@ tzloadbody(char const *name, struct state *sp, bool doextend, sp->charcnt = charcnt; /* Read transitions, discarding those out of time_t range. - But pretend the last transition before time_t_min - occurred at time_t_min. */ + But pretend the last transition before TIME_T_MIN + occurred at TIME_T_MIN. */ timecnt = 0; for (i = 0; i < sp->timecnt; ++i) { int_fast64_t at = stored == 4 ? detzcode(p) : detzcode64(p); - sp->types[i] = at <= time_t_max; + sp->types[i] = at <= TIME_T_MAX; if (sp->types[i]) { time_t attime - = ((TYPE_SIGNED(time_t) ? at < time_t_min : at < 0) - ? time_t_min : at); + = ((TYPE_SIGNED(time_t) ? at < TIME_T_MIN : at < 0) + ? TIME_T_MIN : at); if (timecnt && attime <= sp->ats[timecnt - 1]) { if (attime < sp->ats[timecnt - 1]) return EINVAL; @@ -524,7 +524,7 @@ tzloadbody(char const *name, struct state *sp, bool doextend, /* Leap seconds cannot occur before the Epoch. */ if (tr < 0) return EINVAL; - if (tr <= time_t_max) { + if (tr <= TIME_T_MAX) { /* Leap seconds cannot occur more than once per UTC month, and UTC months are at least 28 days long (minus 1 second for a negative leap second). Each leap second's @@ -1795,12 +1795,12 @@ increment_overflow_time(time_t *tp, int_fast32_t j) { /* ** This is like - ** 'if (! (time_t_min <= *tp + j && *tp + j <= time_t_max)) ...', + ** 'if (! (TIME_T_MIN <= *tp + j && *tp + j <= TIME_T_MAX)) ...', ** except that it does the right thing even if *tp + j would overflow. */ if (! (j < 0 - ? (TYPE_SIGNED(time_t) ? time_t_min - j <= *tp : -1 - j < *tp) - : *tp <= time_t_max - j)) + ? (TYPE_SIGNED(time_t) ? TIME_T_MIN - j <= *tp : -1 - j < *tp) + : *tp <= TIME_T_MAX - j)) return true; *tp += j; return false; @@ -1936,8 +1936,8 @@ time2sub(struct tm *const tmp, /* ** Do a binary search (this works whatever time_t's type is). */ - lo = time_t_min; - hi = time_t_max; + lo = TIME_T_MIN; + hi = TIME_T_MAX; for ( ; ; ) { t = lo / 2 + hi / 2; if (t < lo) @@ -1954,12 +1954,12 @@ time2sub(struct tm *const tmp, } else dir = tmcomp(&mytm, &yourtm); if (dir != 0) { if (t == lo) { - if (t == time_t_max) + if (t == TIME_T_MAX) return WRONG; ++t; ++lo; } else if (t == hi) { - if (t == time_t_min) + if (t == TIME_T_MIN) return WRONG; --t; --hi; diff --git a/private.h b/private.h index 2b07251..f5e39b5 100644 --- a/private.h +++ b/private.h @@ -27,6 +27,21 @@ #define HAVE_DECL_ASCTIME_R 1 #endif +#if !defined HAVE_GENERIC && defined __has_extension +# if __has_extension(c_generic_selections) +# define HAVE_GENERIC 1 +# else +# define HAVE_GENERIC 0 +# endif +#endif +/* _Generic is buggy in pre-4.9 GCC. */ +#if !defined HAVE_GENERIC && defined __GNUC__ +# define HAVE_GENERIC (4 < __GNUC__ + (9 <= __GNUC_MINOR__)) +#endif +#ifndef HAVE_GENERIC +# define HAVE_GENERIC (201112 <= __STDC_VERSION__) +#endif + #ifndef HAVE_GETTEXT #define HAVE_GETTEXT 0 #endif /* !defined HAVE_GETTEXT */ @@ -561,27 +576,32 @@ time_t time2posix_z(timezone_t, time_t) ATTRIBUTE_PURE; #define MINVAL(t, b) \ ((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0)) -/* The minimum and maximum finite time values. This implementation - assumes no padding if time_t is signed and either the compiler is - pre-C11 or time_t is not one of the standard signed integer types. */ -#if 201112 <= __STDC_VERSION__ -static time_t const time_t_min - = (TYPE_SIGNED(time_t) - ? _Generic((time_t) 0, - signed char: SCHAR_MIN, short: SHRT_MIN, - int: INT_MIN, long: LONG_MIN, long long: LLONG_MIN, - default: MINVAL(time_t, TYPE_BIT(time_t))) - : 0); -static time_t const time_t_max - = (TYPE_SIGNED(time_t) - ? _Generic((time_t) 0, - signed char: SCHAR_MAX, short: SHRT_MAX, - int: INT_MAX, long: LONG_MAX, long long: LLONG_MAX, - default: MAXVAL(time_t, TYPE_BIT(time_t))) - : -1); +/* The extreme time values, assuming no padding. */ +#define TIME_T_MIN_NO_PADDING MINVAL(time_t, TYPE_BIT(time_t)) +#define TIME_T_MAX_NO_PADDING MAXVAL(time_t, TYPE_BIT(time_t)) + +/* The extreme time values. These are macros, not constants, so that + any portability problem occur only when compiling .c files that use + the macros, which is safer for applications that need only zdump and zic. + This implementation assumes no padding if time_t is signed and + either the compiler lacks support for _Generic or time_t is not one + of the standard signed integer types. */ +#if HAVE_GENERIC +# define TIME_T_MIN \ + _Generic((time_t) 0, \ + signed char: SCHAR_MIN, short: SHRT_MIN, \ + int: INT_MIN, long: LONG_MIN, long long: LLONG_MIN, \ + default: TIME_T_MIN_NO_PADDING) +# define TIME_T_MAX \ + (TYPE_SIGNED(time_t) \ + ? _Generic((time_t) 0, \ + signed char: SCHAR_MAX, short: SHRT_MAX, \ + int: INT_MAX, long: LONG_MAX, long long: LLONG_MAX, \ + default: TIME_T_MAX_NO_PADDING) \ + : (time_t) -1) #else -static time_t const time_t_min = MINVAL(time_t, TYPE_BIT(time_t)); -static time_t const time_t_max = MAXVAL(time_t, TYPE_BIT(time_t)); +# define TIME_T_MIN TIME_T_MIN_NO_PADDING +# define TIME_T_MAX TIME_T_MAX_NO_PADDING #endif /* -- 2.9.4

1 0

[PROPOSED] Port check_time_t_alternatives to June 8 AIX fix
by Paul Eggert June 16, 2017

June 16, 2017

* private.h (TZ_TIME_T): Declare strftime. This is helpful now that we use our own strftime. Declare strftime_l too, if present. --- private.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/private.h b/private.h index 982ddf3..2b07251 100644 --- a/private.h +++ b/private.h @@ -424,6 +424,12 @@ typedef time_tz tz_time_t; char *ctime(time_t const *); char *ctime_r(time_t const *, char *); double difftime(time_t, time_t) ATTRIBUTE_CONST; +size_t strftime(char *restrict, size_t, char const *restrict, + struct tm const *restrict); +# if HAVE_STRFTIME_L +size_t strftime_l(char *restrict, size_t, char const *restrict, + struct tm const *restrict, locale_t); +# endif struct tm *gmtime(time_t const *); struct tm *gmtime_r(time_t const *restrict, struct tm *restrict); struct tm *localtime(time_t const *); -- 2.9.4

1 0

Re: [tz] 1 s error in America/Adak and America/Nome
by Paul Eggert June 15, 2017

June 15, 2017

On 06/10/2017 07:42 AM, Michael H Deckers wrote: > I do not understand the evidence for the proposed changes. A change of > time scale by 24 h is only observable though the day of the week and > the day number in a calendar (which may be combined with a switch of > calendars), but not through the time of day. > > Where two successive days are observed as Sundays, this is evidence > for the change of time scale having occurred at the instant between > the two. Yes. However, the the question is whether America/Sitka should record the time kept by those in formal control of Sitka, or the time kept by Toomas Ahllund and his fellow workers who made the transition on Sunday in order to have a longer weekend. If the former, the transition should be at 15:30 Friday (Gregorian); if the latter, it should presumably be at 00:00 Sunday (Gregorian). I chose the former, partly because it reflects formal transfer of control, and partly because we have a specific time-of-day recorded for it. > And if a precise instant for the acquisition of Alaska is > to be taken as the instant of the time zone change, then this > assumption > should be applied to all locations (where nothing else is known). > But the proposed changes to tzdb amount to the change happening when > UT = 1867-10-19 + 00:41:37 h for Yakutat > UT = 1867-10-19 + 00:31:13 h for Sitka, Juneau, Metlakatla > UT = 1867-10-19 + 00:31:03 h for Adak, Nome > UT = 1867-10-19 + 00:30:59 h for Anchorage > I do not see support for such variations. Thanks for reporting that; those were due to bugs in my calculations. I installed the attached patch to fix the bugs, and to try to clarify the point you mentioned.

5 12

[PROPOSED] Remove incorrect #endif comments
by Paul Eggert June 14, 2017

June 14, 2017

--- localtime.c | 2 +- private.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/localtime.c b/localtime.c index 1f5bbb2..8c944f3 100644 --- a/localtime.c +++ b/localtime.c @@ -94,7 +94,7 @@ static const char gmt[] = "GMT"; */ #ifndef TZDEFRULESTRING #define TZDEFRULESTRING ",M3.2.0,M11.1.0" -#endif /* !defined TZDEFDST */ +#endif struct ttinfo { /* time type information */ int_fast32_t tt_gmtoff; /* UT offset in seconds */ diff --git a/private.h b/private.h index e6cb21d..982ddf3 100644 --- a/private.h +++ b/private.h @@ -33,7 +33,7 @@ #ifndef HAVE_INCOMPATIBLE_CTIME_R #define HAVE_INCOMPATIBLE_CTIME_R 0 -#endif /* !defined INCOMPATIBLE_CTIME_R */ +#endif #ifndef HAVE_LINK #define HAVE_LINK 1 -- 2.9.4

1 0

[PROPOSED] Remove old Y2K code
by Paul Eggert June 14, 2017

June 14, 2017

The circa-1996 runtime tests to catch potential Y2K problems are no longer worth the maintenance hassle, as the Y2K transition was done many years ago. * Makefile, NEWS: Mention this. * strftime.c (YEAR_2000_NAME, IN_NONE, IN_SOME, IN_THIS, IN_ALL): Remove. All uses removed. (strftime): Do not warn about Y2K problems. (_fmt): Omit last (warning) arg; all uses changed. --- Makefile | 3 --- NEWS | 2 ++ strftime.c | 71 ++++++++++++-------------------------------------------------- 3 files changed, 15 insertions(+), 61 deletions(-) diff --git a/Makefile b/Makefile index 07f4f77..65915ea 100644 --- a/Makefile +++ b/Makefile @@ -162,9 +162,6 @@ LDLIBS= # than what POSIX specifies, assuming local time is UT. # For example, N is 252460800 on AmigaOS. # -Dlocale_t=XXX if your system uses XXX instead of locale_t -# -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU=1 -# if you do not want run time warnings about formats that may cause -# year 2000 grief # -Dssize_t=long on hosts like MS-Windows that lack ssize_t # -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires; # not needed by the main-program tz code, which is single-threaded. diff --git a/NEWS b/NEWS index 2c86e90..40285bf 100644 --- a/NEWS +++ b/NEWS @@ -81,6 +81,8 @@ Unreleased, experimental changes 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. + Y2K runtime checks have been removed, as Y2K was years ago. + 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.) diff --git a/strftime.c b/strftime.c index 173ff8b..9df4176 100644 --- a/strftime.c +++ b/strftime.c @@ -101,19 +101,9 @@ static const struct lc_time_T C_time_locale = { static char * _add(const char *, char *, const char *); static char * _conv(int, const char *, char *, const char *); -static char * _fmt(const char *, const struct tm *, char *, const char *, - int *); +static char * _fmt(const char *, const struct tm *, char *, const char *); static char * _yconv(int, int, bool, bool, char *, char const *); -#ifndef YEAR_2000_NAME -#define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" -#endif /* !defined YEAR_2000_NAME */ - -#define IN_NONE 0 -#define IN_SOME 1 -#define IN_THIS 2 -#define IN_ALL 3 - #if HAVE_STRFTIME_L size_t strftime_l(char *s, size_t maxsize, char const *format, struct tm const *t, @@ -128,24 +118,9 @@ size_t strftime(char *s, size_t maxsize, const char *format, const struct tm *t) { char * p; - int warn; tzset(); - warn = IN_NONE; - p = _fmt(format, t, s, s + maxsize, &warn); -#ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU - if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) { - fprintf(stderr, "\n"); - fprintf(stderr, "strftime format \"%s\" ", format); - fprintf(stderr, "yields only two digits of years in "); - if (warn == IN_SOME) - fprintf(stderr, "some locales"); - else if (warn == IN_THIS) - fprintf(stderr, "the current locale"); - else fprintf(stderr, "all locales"); - fprintf(stderr, "\n"); - } -#endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */ + p = _fmt(format, t, s, s + maxsize); if (p == s + maxsize) return 0; *p = '\0'; @@ -153,8 +128,7 @@ strftime(char *s, size_t maxsize, const char *format, const struct tm *t) } static char * -_fmt(const char *format, const struct tm *t, char *pt, - const char *ptlim, int *warnp) +_fmt(const char *format, const struct tm *t, char *pt, const char *ptlim) { for ( ; *format; ++format) { if (*format == '%') { @@ -200,18 +174,10 @@ label: true, false, pt, ptlim); continue; case 'c': - { - int warn2 = IN_SOME; - - pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2); - if (warn2 == IN_ALL) - warn2 = IN_THIS; - if (warn2 > *warnp) - *warnp = warn2; - } + pt = _fmt(Locale->c_fmt, t, pt, ptlim); continue; case 'D': - pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp); + pt = _fmt("%m/%d/%y", t, pt, ptlim); continue; case 'd': pt = _conv(t->tm_mday, "%02d", pt, ptlim); @@ -232,7 +198,7 @@ label: pt = _conv(t->tm_mday, "%2d", pt, ptlim); continue; case 'F': - pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp); + pt = _fmt("%Y-%m-%d", t, pt, ptlim); continue; case 'H': pt = _conv(t->tm_hour, "%02d", pt, ptlim); @@ -296,10 +262,10 @@ label: pt, ptlim); continue; case 'R': - pt = _fmt("%H:%M", t, pt, ptlim, warnp); + pt = _fmt("%H:%M", t, pt, ptlim); continue; case 'r': - pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp); + pt = _fmt("%I:%M:%S %p", t, pt, ptlim); continue; case 'S': pt = _conv(t->tm_sec, "%02d", pt, ptlim); @@ -322,7 +288,7 @@ label: } continue; case 'T': - pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); + pt = _fmt("%H:%M:%S", t, pt, ptlim); continue; case 't': pt = _add("\t", pt, ptlim); @@ -424,7 +390,6 @@ label: pt = _conv(w, "%02d", pt, ptlim); else if (*format == 'g') { - *warnp = IN_ALL; pt = _yconv(year, base, false, true, pt, ptlim); @@ -439,7 +404,7 @@ label: ** "date as dd-bbb-YYYY" ** (ado, 1993-05-24) */ - pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); + pt = _fmt("%e-%b-%Y", t, pt, ptlim); continue; case 'W': pt = _conv((t->tm_yday + DAYSPERWEEK - @@ -452,21 +417,12 @@ label: pt = _conv(t->tm_wday, "%d", pt, ptlim); continue; case 'X': - pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp); + pt = _fmt(Locale->X_fmt, t, pt, ptlim); continue; case 'x': - { - int warn2 = IN_SOME; - - pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2); - if (warn2 == IN_ALL) - warn2 = IN_THIS; - if (warn2 > *warnp) - *warnp = warn2; - } + pt = _fmt(Locale->x_fmt, t, pt, ptlim); continue; case 'y': - *warnp = IN_ALL; pt = _yconv(t->tm_year, TM_YEAR_BASE, false, true, pt, ptlim); @@ -559,8 +515,7 @@ label: #endif continue; case '+': - pt = _fmt(Locale->date_fmt, t, pt, ptlim, - warnp); + pt = _fmt(Locale->date_fmt, t, pt, ptlim); continue; case '%': /* -- 2.9.4

8 12

Re: [tz] defensive value for define on Solaris causes load of timerule to fail
by Kees Dekker June 13, 2017

June 13, 2017

Retry, now to the mailing list as well. >> So, FILENAME_MAX is probably the better choice, but may be, a >> >> #if FILENAME_MAX < 260 >> #undef FILENAME_MAX >> #define FILENAME_MAX 260 >> #endif >> >> code part is needed? Then FILENAME_MAX is at a defined minimum value >> (of course, the limit of 260 is also quite an arbitrary choice). >I don't like the idea of redefining `FILENAME_MAX`. Just use some >reasonably large value of our choosing for the length of `fullname`. >Even with a modern GNU/Linux `FILENAME_MAX` value of 4096 (on my system >at least), the `fullname` member of `union local_storage` is smaller >than the `u` member. Anything else is also ok, but the union now does not have 'take largest value of somethong' for the fullname member. It is also ok for me to say: #if FILENAME_MAX < 260 #define TZ_FILENAME_MAX 260 #else #define TZ_FILENAME_MAX FILENAME_MAX #endif And use TZ_FILENAME_MAX in the union. My message is just to say 'please take care for platforms where FILENAME_MAX is arbitrary (too) short'. And the value of 14, as used on Solaris, is too short, as some time rules already exceed this length. It makes no sense (i.e. it does not help for the other platforms) in this case that Linux has a much bigger value for this define. As I have checked now, on most platforms, except Solaris, it is 260. Linux uses (as one of the few) a larger value. I've checked HPUX, AIX, Windows, Solaris and several Linux flavors. Kees

7 10

core dumps on AIX7.1 and HPUX11.31 and tzcode 2017B.
by Kees Dekker June 13, 2017

June 13, 2017

Hi, When using the IANA tz data and code (version 2017B) on AIX and/or HPUX, I got core dumps. I was not able to figure out the root cause, but after I had renamed the timezone, daylight and tzname variables to something else (i.e., prefixed with olson_), the error disappeared. A similar crash happened on AIX 7.2, but in only one test case (compared to all our test cases on AIX 7.1 and HPUX 11.31). I don't have a good explanation for the different behavior between AIX 7.1 and 7.2. The tz code was incorporated into two parts of our product: 1. The tzcode was built with USG_COMPAT enabled, i.e. timezone, daylight and tzname symbols are used and incorporated into our binaries 2. The tzcode was also built into a shared library that uses another shared library that calls some of the time functions from libc (e.g. tzset(), or gettimeofday()) BTW: in our code, I'm renaming (using defines) all tz functions too, and prefix them with 'olson_'. So, at symbol level, no duplicates between system functions and TZ code functions should exist. In our code, the error happened under the following circumstances: 1. A binary of us is using the tz library (using USG_COMPAT) 2. That binary loads dynamically (with dlopen(), with RTLD_GLOBAL flag) another shared library of us, also containing the tz library 3. A 3rd party shared library was loaded by our own shared library. Also with dlopen/RTLD_GLOBAL flag. Both our binary (#1) a shared library (#2) were creating using export lists/versions scripts. None of the tz code or variables was exported. And our shared library is using a flag that forces the loader to perform 'innermost symbol resolution' (in such way that C++ exceptions still work). The 3rd party library was either the Oracle or DB2 client database library. Both perform a call to libc that triggers a time function (gettimeofday() or tzset()). The core dump happens in libc, on one of the time functions, called by the 3rd party shared library. Using IANA tz functions from our binaries, without loading 3rd party shared libraries works fine. Hypothesis: the fact that the tzcode (compiled with USG_COMPAT) changes (one of) the (libc exported) timezone, daylight, tzname, causes the time functions in libc to crash. Notes: a. making timezone, daylight, tzname static in the IANA localtime.c and added a get_xxx function did not help either. b. Building without USG_COMPAT did not help either. It is quite strange that none of these both (#a and #b) did help, but I lack time to do more research. As I now have a suitable workaround (by renaming/prefixing involved variables), it is fine for me now. This mail is just intended to inform about conflicts/core dumps, most probably related to 'similar named' variables with the system libc (and thus generate a trap on some platforms). If the tz code can get changed (ever/in the future) to prevent such conflicts, it would be great. No other action is needed (by me) for now. Regards, Kees

2 5

[PROPOSED] Commentary fixes
by Paul Eggert June 12, 2017

June 12, 2017

* Makefile: Mention constraints on TZDIR_BASENAME. * asctime.c: Remove obsolete comment, as zdump now uses snprintf. --- Makefile | 1 + asctime.c | 3 --- 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/Makefile b/Makefile index 05b40bb..07f4f77 100644 --- a/Makefile +++ b/Makefile @@ -49,6 +49,7 @@ TOPDIR= /usr/local # "Compiled" time zone information is placed in the "TZDIR" directory # (and subdirectories). # Use an absolute path name for TZDIR unless you're just testing the software. +# TZDIR_BASENAME should not contain "/" and should not be ".", ".." or empty. TZDIR_BASENAME= zoneinfo TZDIR= $(TOPDIR)/etc/$(TZDIR_BASENAME) diff --git a/asctime.c b/asctime.c index 1613f78..de681ce 100644 --- a/asctime.c +++ b/asctime.c @@ -99,9 +99,6 @@ asctime_r(register const struct tm *timeptr, char *buf) ** (e.g., timeptr->tm_mday) when processing "%Y". */ strftime(year, sizeof year, "%Y", timeptr); - /* - ** We avoid using snprintf since it's not available on all systems. - */ sprintf(result, ((strlen(year) <= 4) ? ASCTIME_FMT : ASCTIME_FMT_B), wn, mn, -- 2.9.4

2 2