- tz - lists.iana.org

winnowing stats
by Zefram Sept. 3, 2013

Sept. 3, 2013

Here are some stats on how much difference winnowing makes to the dataset. Baseline: the source files define 441 distinct zones. Winnowing then reduces the number of distinct zones thus: YEAR COUNT 0000 440 1880 440 1890 439 1900 439 1910 437 1920 435 1930 435 1940 434 1950 425 1960 423 1970 417 1980 391 1990 365 2000 339 2010 313 2020 305 The reduction by one zone for a threshold year of 0000 comes from Pacific/Johnston, a US minor outlying island, which is defined with data identical to the "HST" zone. (Contrary to the usual practice of using LMT for the first segment of geographical zones.) As the two tzfiles are byte-for-byte identical, tzwinnow will merge them regardless of date thresholds. The results for a threshold in the future set a lower limit on the size to which the database can be reduced by this mechanism. Relative to the present full database of 441 zones, it's only a modest gain. Using a threshold later than 1970 for installation purposes will probably only be attractive in a few more decades' time, when there have been many more zone splits arising from contemporary activity. A threshold later than 1970 is currently much more valuable for tzselect purposes. Here it's saving human cognitive load rather than storage space. The reduction in the number of zones is concentrated disproportionately in the countries that have the greatest complexity. This is particularly noticeable with the US zones, the list of which is quite unwieldy in unwinnowed form. Over the period where we attempt complete coverage (1970 to today), the rate at which the number of distinct zones changes is amazingly consistent at 26 per decade. A similar pattern emerges when winnowing with a varying upper date limit, showing that there's a long-term roughly constant rate of zone churn. The number of zones distinct within a single decade is also roughly constant, around 330. The number distinct within a single year hovers around 300, possibly showing a slight rising trend, but I suspect that's an artifact of incomplete data. This suggests that a strategy of winnowing with a moving threshold that remains N years ago will produce a roughly constant zone count. By contrast, the number of zones differing at any time post-1970 (currently 417), or from any other fixed threshold, can grow without bound, and it looks like it will. -zefram

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scope of tz database, scholarship
by Steve Allen Sept. 2, 2013

Sept. 2, 2013

For the sake of the scholarship I would like to see a modification of the current text that reads As for leap seconds, we don't know the history of earth's rotation accurately enough to map SI seconds to historical solar time to more than about one-hour accuracy; see Stephenson FR (2003), Historical eclipses and Earth's rotation, A&G 44: 2.22-2.27 <http://dx.doi.org/10.1046/j.1468-4004.2003.44222.x>. A more complete reference to the accuracy of historical Delta T is in Historical values of the Earth's clock error Delta T and the calculation of eclipses Morrison, L. V. & Stephenson, F. R. Journal for the History of Astronomy (ISSN 0021-8286), Vol. 35, Part 3, No. 120, p. 327 - 336 (2004) as can be seen at http://articles.adsabs.harvard.edu/full/2004JHA....35..327M where, in particular, Table 1 gives uncertainty estimates back nearly 3000 years. For the oldest data there is an addendum Addendum: Historical values of the Earth's clock error Morrison, L. V. & Stephenson, F. R. Journal for the History of Astronomy (ISSN 0021-8286), Vol. 36, Part 3, No. 124, p. 339 (2005) http://adsabs.harvard.edu/full/2005JHA....36..339M In addition to that, for all practical purposes, civil time prior to 1972 did not use SI seconds, but rather mean solar seconds, and for dates prior to 1955 there cannot even be an argument. Therefore in the extended range of the tz database there is an arguably unspecified point when the kind of seconds counted changes from mean solar (UT) to atomic (SI). -- Steve Allen <sla(a)ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m

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Unacceptable recent changes [wasRe: [PATCH 2/4] Move obsolescent Americas entries to 'backward'.]
by Stephen Colebourne Aug. 31, 2013

Aug. 31, 2013

On 26 August 2013 18:16, Paul Eggert <eggert(a)cs.ucla.edu> wrote: > # Shanks & Pottenger say that Atikokan has agreed with Rainy River > # ever since standard time was introduced, but the information from > # McKinnon sounds more authoritative. For now, assume that Atikokan > # switched to EST immediately after WWII era daylight saving time > # ended. This matches the old (less-populous) America/Coral_Harbour > # entry since our cutoff date of 1970, so we can move > -# America/Coral_Harbour to the 'backward' file. > +# America/Coral_Harbour to the 'backward' file. And Atikokan itself > +# is the same as America/Panama since 1970, so we can move > +# America/Atikokan to the 'backward' file as well. > -Zone America/Atikokan -6:06:28 - LMT 1895 > - -6:00 Canada C%sT 1940 Sep 29 > - -6:00 1:00 CDT 1942 Feb 9 2:00s > - -6:00 Canada C%sT 1945 Sep 30 2:00 > - -5:00 - EST So if I understand correctly, all changes to Atikokan before 1970 have just been lost? And they are supposed to use Panama from now on? Here is what JSR-310 can tell us about the two sets of rules: America/Atikokan Transition[Gap at 1895-01-01T00:00-06:06:28 to -06:00] Transition[Gap at 1918-04-14T02:00-06:00 to -05:00] Transition[Overlap at 1918-10-27T02:00-05:00 to -06:00] Transition[Gap at 1940-09-29T00:00-06:00 to -05:00] America/Panama Transition[Overlap at 1890-01-01T00:00-05:18:08 to -05:19:36] Transition[Gap at 1908-04-22T00:00-05:19:36 to -05:00] Merging these is clearly utterly RIDICULOUS. They contain completely different data, and the 1970 argument simply won't wash. Many users will have stored data in databases or other long term storage that refers to these time-zones being made obsolete. When they read the data back, they will get completely different times for historic events - utterly unacceptable. More broadly, no one can pretend that the IDs we use are meaningless. Whether they should or should not have been created this way is not relevent - what matters is that these IDs are meningful and getting rid of them would be a disaster. The IDs are clearly localized, and they have a huge and longstanding usage globally. Panama is nowhere near Atikokan, nor would any reasonable user connect the two. Paul, you need to STOP NOW. You need to reverse the vast majority of your recent changes. Focus on actual changes happening in 2013. Keep the rest of the database totally and utterly stable. And just accept that there is a measure of politics incumbent in time-zones. NONE of these changes should be happening. STABILITY is vital. Stephen

20 53

Proposal for new rules
by Stephen Colebourne Aug. 30, 2013

Aug. 30, 2013

A simple proposal to move forward from where we are with reliable new rules: 1) Each inhabited ISO-3166 region must have at least one fully defined zone (LMT, pre and post 1970) 2) Links must not cross ISO-3166 region bouindaries Some of the rules that would require reworking (not a complete list): Europe/Busingen America/Atikotan America/Aruba America/Anguilla America/Port_of_Spain Europe/Zagreb Europe/Vatican Note that America/Montreal does not require reworking as a result of the first two new rules, although since it looks to have detailed historical information it would be unwise to lose that. Therefore I would add a third rule: 3) Existing pre-1970 data shall be respected If accepted, then these rules would be encoded in the theory file. Stephen

13 27

Acre, Brazil will attempt to re-introduce its previous timezone
by Alexander Krivenyshev Aug. 30, 2013

Aug. 30, 2013

According to the news from Brazil, Acre, Brazil will attempt to re-introduce its previous timezone, excluding Amazonas. http://www.worldtimezone.com/dst_news/dst_news_brazil11.html Alexander Krivenyshev, http://www.WorldTimeZone.com

1 0

Introducing myself
by Stephen Colebourne Aug. 29, 2013

Aug. 29, 2013

On 29 August 2013 20:39, Kevin Lyda <kevin(a)ie.suberic.net> wrote: > No solution will avoid politics. And someone starting a number of threads on > this topic clearly has their own political agenda. I should introduce myself, as not everyone will know who I am, or what I represent. I am Stephen Colebourne - a Java developer of 15+ years - recognised as a Java Champion, a leader in the Java community - author of Joda-Time, the most widely adopted 3rd party API for date and time in Java - co-spec lead of JSR-310, the effort to write a better API for the Java JDK - have written APIs to parse the tzdb - have designed APIs to expose that data to developers - work very closely with Oracle, and have had conversations with CLDR in the past My "political agenda" is to avoid the effort I've put in over the last 12 years on date and time in Java being damaged. Recent changes give the appearance of a lack of understanding of the importance of pre-1970 data and of cross-border localization. I'm sorry that I've had to write so much and object so strongly. I want to find a solution we can all agree on. It seems harder than it should be. Stephen

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Problematic/dubious commits in 2013
by Stephen Colebourne Aug. 29, 2013

Aug. 29, 2013

I have reviewed every commit since the end of 2012. Here are the ones I consider to be problematic. I suggest that others have another review of these, as it may be that not everyone has taken the time to do this. - One zone for each inhabited ISO-3166 region should not have been removed: https://github.com/eggert/tz/commit/d3b025adb25554ee10b986850371e573df92733… - Ensuing changes were wrong: https://github.com/eggert/tz/commit/df99923bde035a263493f3435db63db15df14d53 - Reversion did not revert everything, specifically the reverted links are still in the backward file, not the main file, indicating that they are deprecated which should not be the case (eg for Europe/Zagreb): https://github.com/eggert/tz/commit/ee40570d7d937de749fe89676dec2ff1526ee68b - Pre-1970 damage: https://github.com/eggert/tz/commit/5903db75e5974fbdede1fa05bcef53ff645ac13d https://github.com/eggert/tz/commit/9432f1d23d3c5bbcc14c26f781185c01679edeef - Montreal removal (looks like it changes pre-1970 history) https://github.com/eggert/tz/commit/45dcf69b45087cff50282d4da64b86a7d705ddf3 - Navajo - America/ShipRock removal https://github.com/eggert/tz/commit/d58b59dd8a1e4c10abdbab8857ae521f6c2d2536 https://github.com/eggert/tz/commit/81be53c16b97ce0bc561ce3891ce2503227e3369 - Other possibly dubious commits tzselect changes https://github.com/eggert/tz/commit/cc3f93886bcfe36dfedc8f340827fded6e43539c https://github.com/eggert/tz/commit/ebdf0c5d0ce06b20dcd7e984b7370548f74dc210 Not all of these cause damage, but some clearly do. I'm unhappy with most of them, as they break the principles I value. Stephen

1 0

Principles
by Stephen Colebourne Aug. 29, 2013

Aug. 29, 2013

It seems like there are conflicts in the principles behind the tzdb. Here are my thoughts: What is the tzdb? Generally accepted: - widely used - ubiquitous - reliable - accurate post-1970 - handles changes occurring now More controversial: - IDs used in GUIs (they are whether we like it or not) - IDs have meaning (they do whether we like it or not) - pre-1970 is in-scope (data is there whether we like it or not) - pre-1970 data may not be accurate (users like data, care less about its accuracy) - pre-1970 LMT is accurate for the location in the tzdb ID What do end users expect? (developers and non-developers) - users often pick zones based on raw tzdb ID - users don't know the history of zone rules in their location - users do know that they live in an area that might have special zone rules, eg. Busingen/Navajo - users want minimal cognitive effort, pick it and it works - users don't understand the nuances of a cross-border zone, they just associate with their region What do I expect? - Stability - No deletions of data, except where _proven_ wrong - Additions focussed on today and the future - Historical changes only following research - No new time-zones in the main files unless they differ post-1970 - At least one time-zone ID for each ISO-3166 region - Using all files except backward should meet goals above - Backward file is for deprecations only I don't think that any of this is unreasonable, or different from how the tzdb has previously worked. Stephen

1 0

Namibia Time Change
by Hank W. Aug. 26, 2013

Aug. 26, 2013

Reminder: The annual switch from West Africa Time (UTC+1) to West Africa Summer Time (UTC+2) in Namibia only is scheduled for this coming Sunday, 1 September, at 2 AM WAT (1 AM UTC).

2 2

Unable to get the tz database
by Peddi, Radhika (Radhika) Aug. 24, 2013

Aug. 24, 2013

Hi, This is Radhika from Avaya. When I am trying to get tz database from the link http://www.twinsun.com/tz/tz-link.htm, by using FTP distribution, I am getting Host Not Found error. Please find the attached screen shot for the same. When I am using below shell command on my linux setup wget 'ftp://elsie.nci.nih.gov/pub/tz*.tar.gz', I am getting below error --2013-08-20 03:14:03-- ftp://elsie.nci.nih.gov/pub/tz*.tar.gz => `.listing' Resolving elsie.nci.nih.gov... failed: Name or service not known. wget: unable to resolve host address `elsie.nci.nih.gov' Could you please help me how to get rid of this problem. Thanks & Regards, Radhika Peddi|Avaya India Pvt. Ltd.| Wing 'A', Level -5, Tower-11, Cybercity, Magarpatta City, Hadapsar | Pune, 411028|India Voice +91 20 4101 8311| Email: rpeddi<mailto:rpeddi@avaya.com>@avaya.com [ Please consider the environment before printing this email ]

2 3

infinite loop in time2sub
by enh Aug. 22, 2013

Aug. 22, 2013

i recently upgraded Android's copy of tzcode to be closer to tzcode2013d. with Android's signed 32-bit time_t i'm seeing a change in behavior for out-of-range dates. previously given something like this, mktime would return an error, but now it hangs in the binary search in time2sub. struct tm t; memset(&t, 0, sizeof(tm)); t.tm_year = 200; t.tm_mon = 2; t.tm_mday = 10; changing the if (t == lo) { ++t; if (t <= lo) return WRONG; ++lo; } else if (t == hi) { --t; if (t >= hi) return WRONG; --hi; } back to if (t == lo) { if (t == TIME_T_MAX) return WRONG; ++t; ++lo; } else if (t == hi) { if (t == TIME_T_MIN) return WRONG; --t; --hi; } fixes things. looking at the git history in https://github.com/eggert/tz.gitit looks like the old code, found in Android up to and including jb-mr2 (but no longer in AOSP ToT), was never in upstream tzcode. here's where the upstream tzcode's overflow checks were introduced: commit 46fa7e98177cae664f673c6034c9ac74d0ccd0ec Author: Arthur David Olson <olsona@elsie> Date: Tue Aug 9 09:55:06 2005 -0400 overflow work SCCS-file: localtime.c SCCS-SID: 7.96 diff --git a/localtime.c b/localtime.c index 1c3e9b0..d3edb5a 100644 --- a/localtime.c +++ b/localtime.c @@ -1616,9 +1616,13 @@ const int do_norm_secs; if (dir != 0) { if (t == lo) { ++t; + if (t <= lo) + return WRONG; ++lo; } else if (t == hi) { --t; + if (t >= hi) + return WRONG; --hi; } if (lo > hi) looking at the Android AOSP git history, it looks like we found and fixed this bug years ago but never talked to upstream about it: commit 2093d350be21ff086f9e145404877941b9a42c5c Author: David 'Digit' Turner <digit(a)google.com> Date: Wed Sep 9 17:41:59 2009 -0700 Fix an infinite loop in time2sub. The problem is that time_t is signed, and the original code relied on the fact that (X + c < X) in case of overflow for c >= 0. Unfortunately, this condition is only guaranteed by the standard for unsigned arithmetic, and the gcc 4.4.0 optimizer did completely remove the corresponding test from the code. This resulted in a missing boundary check, and an infinite loop. The problem is solved by testing explicitely for TIME_T_MIN and TIME_T_MAX in the loop that uses this. Also fix increment_overflow and long_increment_overflow which were buggy for exactly the same reasons. Note: a similar fix is needed for system/core/libcutils diff --git a/libc/tzcode/localtime.c b/libc/tzcode/localtime.c index 9c5f218..83c1011 100644 --- a/libc/tzcode/localtime.c +++ b/libc/tzcode/localtime.c @@ -75,6 +75,31 @@ static __inline__ void _tzUnlock(void) pthread_mutex_unlock(&_tzMutex); } +/* Complex computations to determine the min/max of time_t depending + * on TYPE_BIT / TYPE_SIGNED / TYPE_INTEGRAL. + * These macros cannot be used in pre-processor directives, so we + * let the C compiler do the work, which makes things a bit funky. + */ +static const time_t TIME_T_MAX = + TYPE_INTEGRAL(time_t) ? + ( TYPE_SIGNED(time_t) ? + ~((time_t)1 << (TYPE_BIT(time_t)-1)) + : + ~(time_t)0 + ) + : /* if time_t is a floating point number */ + ( sizeof(time_t) > sizeof(float) ? (time_t)DBL_MAX : (time_t)FLT_MAX ); + +static const time_t TIME_T_MIN = + TYPE_INTEGRAL(time_t) ? + ( TYPE_SIGNED(time_t) ? + ((time_t)1 << (TYPE_BIT(time_t)-1)) + : + 0 + ) + : + ( sizeof(time_t) > sizeof(float) ? (time_t)DBL_MIN : (time_t)FLT_MIN ); + #ifndef WILDABBR /* ** Someone might make incorrect use of a time zone abbreviation: @@ -1683,11 +1708,16 @@ increment_overflow(number, delta) int * number; int delta; { - int number0; + unsigned number0 = (unsigned)*number; + unsigned number1 = (unsigned)(number0 + delta); + + *number = (int)number1; - number0 = *number; - *number += delta; - return (*number < number0) != (delta < 0); + if (delta >= 0) { + return ((int)number1 < (int)number0); + } else { + return ((int)number1 > (int)number0); + } } static int @@ -1695,11 +1725,16 @@ long_increment_overflow(number, delta) long * number; int delta; { - long number0; + unsigned long number0 = (unsigned long)*number; + unsigned long number1 = (unsigned long)(number0 + delta); + + *number = (long)number1; - number0 = *number; - *number += delta; - return (*number < number0) != (delta < 0); + if (delta >= 0) { + return ((long)number1 < (long)number0); + } else { + return ((long)number1 > (long)number0); + } } static int @@ -1868,14 +1903,14 @@ const int do_norm_secs; } else dir = tmcomp(&mytm, &yourtm); if (dir != 0) { if (t == lo) { - ++t; - if (t <= lo) + if (t == TIME_T_MAX) return WRONG; + ++t; ++lo; } else if (t == hi) { - --t; - if (t >= hi) + if (t == TIME_T_MIN) return WRONG; + --t; --hi; } if (lo > hi) right now i'm going to work around this by building the tzcode part of the C library with -fno-strict-overflow (because i don't know how many other places are relying on this unspecified behavior), but i'll apply whatever patch goes into upstream as soon as it's available. --elliott

2 2

[PATCH] * .gitignore: Add 'date'.
by Paul Eggert Aug. 22, 2013

Aug. 22, 2013

--- .gitignore | 1 + 1 file changed, 1 insertion(+) diff --git a/.gitignore b/.gitignore index 5759d2a..18dbbcc 100644 --- a/.gitignore +++ b/.gitignore @@ -4,6 +4,7 @@ *.txt *~ ChangeLog +date leapseconds time.tab tzselect -- 1.7.11.7

1 0

[PATCH] tzselect: new options -c COORD and -n LIMIT
by Paul Eggert Aug. 22, 2013

Aug. 22, 2013

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. --- tzselect.8 | 26 ++++++++++ tzselect.ksh | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 177 insertions(+), 11 deletions(-) diff --git a/tzselect.8 b/tzselect.8 index b5e2c88..884af36 100644 --- a/tzselect.8 +++ b/tzselect.8 @@ -4,6 +4,12 @@ tzselect \- select a time zone .SH SYNOPSIS .B tzselect [ +.B \-c +.I coord +] [ +.B \-n +.I limit +] [ .B \-t .I zonetabtype ] [ @@ -21,6 +27,26 @@ The output is suitable as a value for the TZ environment variable. All interaction with the user is done via standard input and standard error. .SH OPTIONS .TP +.BI "\-c " coord +Instead of asking for continent and then country and then city, +ask for selection from time zones whose largest cities +are closest to the location with geographical coordinates +.IR coord . +Use ISO 6709 notation for +.IR coord , +for example, +.B "\-c\ \+42.391415\-071.570419" +for 42.391415\(de\|N, 71.570419\(de\|W, and +.B "\-c\ +404226\-0740319" +for 48\(de\|42\(fm\|26\(sd\|N, 74\(de\|3\(fm\|19\(sd\|W. +.TP +.BI "\-n " limit +When +.B \-c +is used, display the closest +.I limit +locations (default 10). +.TP .BI "\-t " zonetabtype Make selections from the time zone table of type .IR zonetabtype . diff --git a/tzselect.ksh b/tzselect.ksh index dc9f256..da6adb2 100644 --- a/tzselect.ksh +++ b/tzselect.ksh @@ -1,5 +1,7 @@ #!/bin/bash +export LC_ALL=C + PKGVERSION='(tzcode) ' TZVERSION=see_Makefile REPORT_BUGS_TO=tz(a)iana.org @@ -41,15 +43,43 @@ ZONETABTYPE=zone exit 1 } -usage="Usage: tzselect [--version] [--help] [-t ZONETABTYPE] +coord= +location_limit=10 + +usage="Usage: tzselect [--version] [--help] [-c COORD] [-n LIMIT] [-t ZONETABTYPE] Select a time zone interactively. -ZONETABTYPE should be one of 'time' or 'zone'. + +Options: + + -c COORD + Instead of asking for continent and then country and then city, + ask for selection from time zones whose largest cities + are closest to the location with geographical coordinates COORD. + COORD should use ISO 6709 notation, for example, '-c +4852+00220' + for Paris. + + -n LIMIT + Display at most LIMIT locations when -c is used (default $location_limit). + + -t ZONETABTYPE + Use time zone table ZONETABTYPE. ZONETABTYPE should be one of + 'time' or 'zone'. + + --version + Output version information. + + --help + Output this help. Report bugs to $REPORT_BUGS_TO." -while getopts t:-: opt +while getopts c:n:t:-: opt do case $opt$OPTARG in + c*) + coord=$OPTARG ;; + n*) + location_limit=$OPTARG ;; t*) ZONETABTYPE=$OPTARG ;; -help) @@ -90,6 +120,66 @@ case $(echo 1 | (select x in x; do break; done) 2>/dev/null) in ?*) PS3= esac +# Awk script to read a time zone table and output the same table, +# with each column preceded by its distance from 'here'. +output_distances=' + BEGIN { + FS = "\t" + while (getline <TZ_COUNTRY_TABLE) + if ($0 ~ /^[^#]/) + country[$1] = $2 + country["US"] = "US" # Otherwise the strings get too long. + } + function cvt1(coord, deg, min, ilen, sign, sec) { + ilen = length(coord) + sign = substr(coord, 1, 1) + if (coord ~ /\./) { + deg = coord + 0 + } else { + if (ilen <= 6) { + sec = 0 + } else { + sec = sign substr(coord, ilen - 1) + ilen -= 2 + } + min = sign substr(coord, ilen - 1, 2) + deg = substr(coord, 1, ilen - 2) + deg = (deg * 3600.0 + min * 60.0 + sec) / 3600.0 + } + return deg * 0.017453292519943295 + } + function convert_latitude(coord) { + match(coord, /..*[-+]/) + return cvt1(substr(coord, 1, RLENGTH - 1)) + } + function convert_longitude(coord) { + match(coord, /..*[-+]/) + return cvt1(substr(coord, RLENGTH)) + } + # Great-circle distance between points with given latitude and longitude. + # Inputs and output are in radians. This uses the great-circle special + # case of the Vicenty formula for distances on ellipsoids. + function dist(lat1, long1, lat2, long2, dlong, x, y, num, denom) { + dlong = long2 - long1 + x = cos (lat2) * sin (dlong) + y = cos (lat1) * sin (lat2) - sin (lat1) * cos (lat2) * cos (dlong) + num = sqrt (x * x + y * y) + denom = sin (lat1) * sin (lat2) + cos (lat1) * cos (lat2) * cos (dlong) + return atan2(num, denom) + } + BEGIN { + coord_lat = convert_latitude(coord) + coord_long = convert_longitude(coord) + } + /^[^#]/ { + here_lat = convert_latitude($2) + here_long = convert_longitude($2) + line = $1 "\t" $2 "\t" $3 "\t" country[$1] + if (NF == 4) + line = line " - " $4 + printf "%g\t%s\n", dist(coord_lat, coord_long, here_lat, here_long), line + } +' # Begin the main loop. We come back here if the user wants to retry. while @@ -101,10 +191,14 @@ while country= region= + case $coord in + ?*) + continent=coord;; + '') # Ask the user for continent or ocean. - echo >&2 'Please select a continent or ocean.' + echo >&2 'Please select a continent, ocean, "coord", or "TZ".' select continent in \ Africa \ @@ -117,7 +211,8 @@ while Europe \ 'Indian Ocean' \ 'Pacific Ocean' \ - 'none - I want to specify the time zone using the Posix TZ format.' + 'coord - I want to use geographical coordinates.' \ + 'TZ - I want to specify the time zone using the Posix TZ format.' do case $continent in '') @@ -130,10 +225,12 @@ while break esac done + esac + case $continent in '') exit 1;; - none) + TZ) # Ask the user for a Posix TZ string. Check that it conforms. while echo >&2 'Please enter the desired value' \ @@ -158,6 +255,45 @@ while done TZ_for_date=$TZ;; *) + case $continent in + coord) + case $coord in + '') + echo >&2 'Please enter coordinates' \ + 'in ISO 6709 notation.' + echo >&2 'For example, +4042-07403 stands for' + echo >&2 '40 degrees 42 minutes north,' \ + '74 degrees 3 minutes west.' + read coord;; + esac + distance_table=$($AWK \ + -v coord="$coord" \ + -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \ + "$output_distances" <$TZ_ZONE_TABLE | + sort -n | + sed "${location_limit}q" + ) + regions=$(echo "$distance_table" | $AWK ' + BEGIN { FS = "\t" } + { print $NF } + ') + echo >&2 'Please select one of the following' \ + 'time zone regions,' + echo >&2 'listed roughly in increasing order' \ + "of distance from $coord". + select region in $regions + do + case $region in + '') echo >&2 'Please enter a number in range.';; + ?*) break;; + esac + done + TZ=$(echo "$distance_table" | $AWK -v region="$region" ' + BEGIN { FS="\t" } + $NF == region { print $4 } + ') + ;; + *) # Get list of names of countries in the continent or ocean. countries=$($AWK -F'\t' \ -v continent="$continent" \ @@ -185,7 +321,8 @@ while # If there's more than one country, ask the user which one. case $countries in *"$newline"*) - echo >&2 'Please select a country.' + echo >&2 'Please select a country' \ + 'whose clocks agree with yours.' select country in $countries do case $country in @@ -256,6 +393,7 @@ while } $1 == cc && $4 == region { print $3 } ' <$TZ_ZONE_TABLE) + esac # Make sure the corresponding zoneinfo file exists. TZ_for_date=$TZDIR/$TZ @@ -292,9 +430,11 @@ Universal Time is now: $UTdate." echo >&2 "" echo >&2 "The following information has been given:" echo >&2 "" - case $country+$region in - ?*+?*) echo >&2 " $country$newline $region";; - ?*+) echo >&2 " $country";; + case $country%$region%$coord in + ?*%?*%) echo >&2 " $country$newline $region";; + ?*%%) echo >&2 " $country";; + %?*%?*) echo >&2 " coord $coord$newline $region";; + %%?*) echo >&2 " coord $coord";; +) echo >&2 " TZ='$TZ'" esac echo >&2 "" @@ -313,7 +453,7 @@ Universal Time is now: $UTdate." '') exit 1;; Yes) break esac -do : +do coord= done case $SHELL in -- 1.8.1.2

3 7

[PATCH 1/3] Further removal of attempt to support floating-point time_t.
by Paul Eggert Aug. 19, 2013

Aug. 19, 2013

* localtime.c (timesub): * zdump.c (my_localtime): Don't worry about time_t being floating-point. * localtime.c (timesub): Avoid undefined behavior on integer overflow when assigning time_t to int. --- localtime.c | 5 +++-- zdump.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/localtime.c b/localtime.c index 5312ad9..f58b20a 100644 --- a/localtime.c +++ b/localtime.c @@ -1489,9 +1489,10 @@ timesub(const time_t *const timep, const int_fast32_t offset, register int leapdays; tdelta = tdays / DAYSPERLYEAR; - idelta = tdelta; - if (tdelta - idelta >= 1 || idelta - tdelta >= 1) + if (! ((! TYPE_SIGNED(time_t) || INT_MIN <= tdelta) + && tdelta <= INT_MAX)) return NULL; + idelta = tdelta; if (idelta == 0) idelta = (tdays < 0) ? -1 : 1; newy = y; diff --git a/zdump.c b/zdump.c index 36c1838..fa5f8d8 100644 --- a/zdump.c +++ b/zdump.c @@ -244,7 +244,7 @@ my_localtime(time_t *tp) tm = *tmp; t = mktime(&tm); - if (t - *tp >= 1 || *tp - t >= 1) { + if (t != *tp) { (void) fflush(stdout); (void) fprintf(stderr, "\n%s: ", progname); (void) fprintf(stderr, tformat(), *tp); -- 1.8.1.2

3 7

Re: [tz] Problem with Busingen
by Paul Eggert Aug. 19, 2013

Aug. 19, 2013

Luca Marzolla wrote: > It is possible to fix this minor inconvenience in the next release? Yes. The problem should already be fixed in the experimental version, which you can get from Github, here: https://github.com/eggert/tz It's fixed in a different way, by the way: the Busingen link got moved to a different file. See: https://github.com/eggert/tz/commit/df99923bde035a263493f3435db63db15df14d53

1 0

Mushroom clowds are forming…
by Steffen Daode Nurpmeso Aug. 17, 2013

Aug. 17, 2013

So if there is a button, someone surely is going to press it. --steffen

1 0

[PATCH] * date.c (nondigit): Add ATTRIBUTE_PURE, to pacify GCC 4.8.1.
by Paul Eggert Aug. 17, 2013

Aug. 17, 2013

--- date.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/date.c b/date.c index 4355a7b..d8ff50e 100644 --- a/date.c +++ b/date.c @@ -497,7 +497,7 @@ errensure(void) retval = EXIT_FAILURE; } -static const char * +static const char * ATTRIBUTE_PURE nondigit(register const char *cp) { while (is_digit(*cp)) -- 1.7.11.7

1 0

[PATCH] * zdump.c: Minor integer-size porting fixes.
by Paul Eggert Aug. 17, 2013

Aug. 17, 2013

(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. --- zdump.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/zdump.c b/zdump.c index fa5f8d8..3d5ec64 100644 --- a/zdump.c +++ b/zdump.c @@ -452,7 +452,7 @@ main(int argc, char *argv[]) t = absolute_min_time; if (!Vflag) { show(argv[i], t, TRUE); - t += SECSPERHOUR * HOURSPERDAY; + t += SECSPERDAY; show(argv[i], t, TRUE); } if (t < cutlotime) @@ -463,9 +463,11 @@ main(int argc, char *argv[]) (void) strncpy(buf, abbr(&tm), (sizeof buf) - 1); } for ( ; ; ) { - if (t >= cuthitime || t >= cuthitime - SECSPERHOUR * 12) + newt = (t < absolute_max_time - SECSPERDAY / 2 + ? t + SECSPERDAY / 2 + : absolute_max_time); + if (cuthitime <= newt) break; - newt = t + SECSPERHOUR * 12; newtmp = localtime(&newt); if (newtmp != NULL) newtm = *newtmp; @@ -488,9 +490,9 @@ main(int argc, char *argv[]) } if (!Vflag) { t = absolute_max_time; - t -= SECSPERHOUR * HOURSPERDAY; + t -= SECSPERDAY; show(argv[i], t, TRUE); - t += SECSPERHOUR * HOURSPERDAY; + t += SECSPERDAY; show(argv[i], t, TRUE); } } -- 1.7.11.7

1 0

[PATCH] * zdump.c: Tune performance of -c with large numbers on 64-bit hosts.
by Paul Eggert Aug. 15, 2013

Aug. 15, 2013

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. --- zdump.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 46 insertions(+), 17 deletions(-) diff --git a/zdump.c b/zdump.c index 788020a..36c1838 100644 --- a/zdump.c +++ b/zdump.c @@ -60,9 +60,15 @@ typedef int int_fast32_t; # if defined LLONG_MAX || defined __LONG_LONG_MAX__ typedef long long intmax_t; # define PRIdMAX "lld" +# ifdef LLONG_MAX +# define INTMAX_MAX LLONG_MAX +# else +# define INTMAX_MAX __LONG_LONG_MAX__ +# endif # else typedef long intmax_t; # define PRIdMAX "ld" +# define INTMAX_MAX LONG_MAX # endif #endif #ifndef SCNdMAX @@ -140,6 +146,17 @@ typedef long intmax_t; #define SECSPERDAY ((int_fast32_t) SECSPERHOUR * HOURSPERDAY) #define SECSPERNYEAR (SECSPERDAY * DAYSPERNYEAR) #define SECSPERLYEAR (SECSPERNYEAR + SECSPERDAY) +#define SECSPER400YEARS (SECSPERNYEAR * (intmax_t) (300 + 3) \ + + SECSPERLYEAR * (intmax_t) (100 - 3)) + +/* +** True if SECSPER400YEARS is known to be representable as an +** intmax_t. It's OK that SECSPER400YEARS_FITS can in theory be false +** even if SECSPER400YEARS is representable, because when that happens +** the code merely runs a bit more slowly, and this slowness doesn't +** occur on any practical platform. +*/ +enum { SECSPER400YEARS_FITS = SECSPERLYEAR <= INTMAX_MAX / 400 }; #ifndef HAVE_GETTEXT #define HAVE_GETTEXT 0 @@ -490,30 +507,42 @@ main(int argc, char *argv[]) static time_t yeartot(const intmax_t y) { - register intmax_t myy; - register int_fast32_t seconds; + register intmax_t myy, seconds, years; register time_t t; myy = EPOCH_YEAR; t = 0; - while (myy != y) { - if (myy < y) { + while (myy < y) { + if (SECSPER400YEARS_FITS && 400 <= y - myy) { + intmax_t diff400 = (y - myy) / 400; + if (INTMAX_MAX / SECSPER400YEARS < diff400) + return absolute_max_time; + seconds = diff400 * SECSPER400YEARS; + years = diff400 * 400; + } else { seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR; - ++myy; - if (t > absolute_max_time - seconds) { - t = absolute_max_time; - break; - } - t += seconds; + years = 1; + } + myy += years; + if (t > absolute_max_time - seconds) + return absolute_max_time; + t += seconds; + } + while (y < myy) { + if (SECSPER400YEARS_FITS && y + 400 <= myy && myy < 0) { + intmax_t diff400 = (myy - y) / 400; + if (INTMAX_MAX / SECSPER400YEARS < diff400) + return absolute_min_time; + seconds = diff400 * SECSPER400YEARS; + years = diff400 * 400; } else { - --myy; - seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR; - if (t < absolute_min_time + seconds) { - t = absolute_min_time; - break; - } - t -= seconds; + seconds = isleap(myy - 1) ? SECSPERLYEAR : SECSPERNYEAR; + years = 1; } + myy -= years; + if (t < absolute_min_time + seconds) + return absolute_min_time; + t -= seconds; } return t; } -- 1.8.1.2

2 2

[PATCH 1/4] * date.c: Pacify GCC 4.7.3.
by Paul Eggert Aug. 15, 2013

Aug. 15, 2013

(atof, getlogin, mktime, strchr, time, strftime): Remove old-style declarations. GCC 4.7.3 warns about them, and they aren't needed nowadays anyway. (main) [HAVE_SETTIMEOFDAY != 2]: "Use" dsttime and minuteswest to pacify GCC 4.7.3. --- date.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/date.c b/date.c index 047969f..bae90f3 100644 --- a/date.c +++ b/date.c @@ -54,14 +54,9 @@ static char sccsid[] = "@(#)date.c 4.23 (Berkeley) 9/20/88"; #define SECSPERMIN 60 #endif /* !defined SECSPERMIN */ -extern double atof(); extern char ** environ; -extern char * getlogin(); -extern time_t mktime(); extern char * optarg; extern int optind; -extern char * strchr(); -extern time_t time(); extern char * tzname[2]; static int retval = EXIT_SUCCESS; @@ -270,6 +265,8 @@ _("date: error: multiple values in command line\n")); oops("settimeofday"); #endif /* HAVE_SETTIMEOFDAY == 2 */ #if HAVE_SETTIMEOFDAY != 2 + (void) dsttime; + (void) minuteswest; (void) fprintf(stderr, _("date: warning: kernel doesn't keep -d/-t information, option ignored\n")); #endif /* HAVE_SETTIMEOFDAY != 2 */ @@ -543,8 +540,6 @@ display(const char *const format) exit(retval); } -extern size_t strftime(); - #define INCR 1024 static void -- 1.8.1.2

15 32

[PATCH 1/2] * .gitignore: Add 'leapseconds'.
by Paul Eggert Aug. 14, 2013

Aug. 14, 2013

This follows up on the previous change, since 'leapseconds' is now generated automatically. --- .gitignore | 1 + 1 file changed, 1 insertion(+) diff --git a/.gitignore b/.gitignore index 5edf101..21c798d 100644 --- a/.gitignore +++ b/.gitignore @@ -4,6 +4,7 @@ *.txt *~ ChangeLog +leapseconds tzselect version.h yearistype -- 1.7.11.7

1 1

Re: [tz] Proposal regarding tz DB and leap second updates
by Paul Eggert Aug. 13, 2013

Aug. 13, 2013

Bradley White privately sent a Perl script to generate 'leapseconds' from the NIST leap-seconds.list file. Since we use POSIX Awk for the other processing it's probably better to use Awk here, too, so here's a proposed patch with all the Makefile bells and whistles, which I pushed to the experimental github repository. The patch removes the file 'leapseconds' from the repository because it's now generated automatically. I took the liberty of removing the copy of the IERS announcement from the generated 'leapseconds' since its copyright status was unclear. The NIST leap-seconds.list file is public domain, so it's OK for us to redistribute it. >From 459b72d3edec98488e5132d4473c4678b4ed5a73 Mon Sep 17 00:00:00 2001 From: Paul Eggert <eggert(a)cs.ucla.edu> Date: Mon, 12 Aug 2013 23:58:29 -0700 Subject: [PATCH] Generate the 'leapseconds' file automatically from leap-seconds.list. * leap-seconds.list: New file, copied from the NIST. * leapseconds: Remove from git; it's now generated. * leapseconds.awk: New file. * Makefile (DATA): Add leap-seconds.list. Remove leapseconds. (MISC): Add leapseconds.awk. (leapseconds): New rule. (right_posix, posix_right): Depend on leapseconds. (clean_misc): Remove leapseconds. --- Makefile | 14 ++-- leap-seconds.list | 231 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ leapseconds | 100 ----------------------- leapseconds.awk | 68 ++++++++++++++++ 4 files changed, 308 insertions(+), 105 deletions(-) create mode 100644 leap-seconds.list delete mode 100644 leapseconds create mode 100644 leapseconds.awk diff --git a/Makefile b/Makefile index db7f56e..68d7132 100644 --- a/Makefile +++ b/Makefile @@ -318,10 +318,11 @@ NDATA= systemv factory SDATA= solar87 solar88 solar89 TDATA= $(YDATA) $(NDATA) $(SDATA) TABDATA= iso3166.tab zone.tab -DATA= $(YDATA) $(NDATA) $(SDATA) $(TABDATA) leapseconds yearistype.sh +DATA= $(YDATA) $(NDATA) $(SDATA) $(TABDATA) \ + leap-seconds.list yearistype.sh WEB_PAGES= tz-art.htm tz-link.htm MISC= usno1988 usno1989 usno1989a usno1995 usno1997 usno1998 \ - $(WEB_PAGES) checktab.awk workman.sh \ + $(WEB_PAGES) checktab.awk leapseconds.awk workman.sh \ zoneinfo2tdf.pl ENCHILADA= $(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) @@ -375,6 +376,9 @@ yearistype: yearistype.sh cp yearistype.sh yearistype chmod +x yearistype +leapseconds: leapseconds.awk leap-seconds.list + $(AWK) -f leapseconds.awk leap-seconds.list >$@ + posix_only: zic $(TDATA) $(ZIC) -y $(YEARISTYPE) -d $(TZDIR) -L /dev/null $(TDATA) @@ -390,14 +394,14 @@ right_only: zic leapseconds $(TDATA) # Therefore, the other two directories are now siblings of $(TZDIR). # You must replace all of $(TZDIR) to switch from not using leap seconds # to using them, or vice versa. -right_posix: right_only +right_posix: right_only leapseconds rm -fr $(TZDIR)-leaps ln -s $(TZDIR_BASENAME) $(TZDIR)-leaps || \ $(ZIC) -y $(YEARISTYPE) \ -d $(TZDIR)-leaps -L leapseconds $(TDATA) $(ZIC) -y $(YEARISTYPE) -d $(TZDIR)-posix -L /dev/null $(TDATA) -posix_right: posix_only +posix_right: posix_only leapseconds rm -fr $(TZDIR)-posix ln -s $(TZDIR_BASENAME) $(TZDIR)-posix || \ $(ZIC) -y $(YEARISTYPE) \ @@ -440,7 +444,7 @@ check_web: $(WEB_PAGES) clean_misc: rm -f core *.o *.out \ - date tzselect version.h zdump zic yearistype + date leapseconds tzselect version.h zdump zic yearistype clean: clean_misc rm -f -r tzpublic diff --git a/leap-seconds.list b/leap-seconds.list new file mode 100644 index 0000000..7df3de6 --- /dev/null +++ b/leap-seconds.list @@ -0,0 +1,231 @@ +# +# In the following text, the symbol '#' introduces +# a comment, which continues from that symbol until +# the end of the line. A plain comment line has a +# whitespace character following the comment indicator. +# There are also special comment lines defined below. +# A special comment will always have a non-whitespace +# character in column 2. +# +# A blank line should be ignored. +# +# The following table shows the corrections that must +# be applied to compute International Atomic Time (TAI) +# from the Coordinated Universal Time (UTC) values that +# are transmitted by almost all time services. +# +# The first column shows an epoch as a number of seconds +# since 1900.0 and the second column shows the number of +# seconds that must be added to UTC to compute TAI for +# any timestamp at or after that epoch. The value on +# each line is valid from the indicated initial instant +# until the epoch given on the next one or indefinitely +# into the future if there is no next line. +# (The comment on each line shows the representation of +# the corresponding initial epoch in the usual +# day-month-year format. The epoch always begins at +# 00:00:00 UTC on the indicated day. See Note 5 below.) +# +# Important notes: +# +# 1. Coordinated Universal Time (UTC) is often referred to +# as Greenwich Mean Time (GMT). The GMT time scale is no +# longer used, and the use of GMT to designate UTC is +# discouraged. +# +# 2. The UTC time scale is realized by many national +# laboratories and timing centers. Each laboratory +# identifies its realization with its name: Thus +# UTC(NIST), UTC(USNO), etc. The differences among +# these different realizations are typically on the +# order of a few nanoseconds (i.e., 0.000 000 00x s) +# and can be ignored for many purposes. These differences +# are tabulated in Circular T, which is published monthly +# by the International Bureau of Weights and Measures +# (BIPM). See www.bipm.fr for more information. +# +# 3. The current defintion of the relationship between UTC +# and TAI dates from 1 January 1972. A number of different +# time scales were in use before than epoch, and it can be +# quite difficult to compute precise timestamps and time +# intervals in those "prehistoric" days. For more information, +# consult: +# +# The Explanatory Supplement to the Astronomical +# Ephemeris. +# or +# Terry Quinn, "The BIPM and the Accurate Measurement +# of Time," Proc. of the IEEE, Vol. 79, pp. 894-905, +# July, 1991. +# +# 4. The insertion of leap seconds into UTC is currently the +# responsibility of the International Earth Rotation Service, +# which is located at the Paris Observatory: +# +# Central Bureau of IERS +# 61, Avenue de l'Observatoire +# 75014 Paris, France. +# +# Leap seconds are announced by the IERS in its Bulletin C +# +# See hpiers.obspm.fr or www.iers.org for more details. +# +# All national laboratories and timing centers use the +# data from the BIPM and the IERS to construct their +# local realizations of UTC. +# +# Although the definition also includes the possibility +# of dropping seconds ("negative" leap seconds), this has +# never been done and is unlikely to be necessary in the +# foreseeable future. +# +# 5. If your system keeps time as the number of seconds since +# some epoch (e.g., NTP timestamps), then the algorithm for +# assigning a UTC time stamp to an event that happens during a positive +# leap second is not well defined. The official name of that leap +# second is 23:59:60, but there is no way of representing that time +# in these systems. +# Many systems of this type effectively stop the system clock for +# one second during the leap second and use a time that is equivalent +# to 23:59:59 UTC twice. For these systems, the corresponding TAI +# timestamp would be obtained by advancing to the next entry in the +# following table when the time equivalent to 23:59:59 UTC +# is used for the second time. Thus the leap second which +# occurred on 30 June 1972 at 23:59:59 UTC would have TAI +# timestamps computed as follows: +# +# ... +# 30 June 1972 23:59:59 (2287785599, first time): TAI= UTC + 10 seconds +# 30 June 1972 23:59:60 (2287785599,second time): TAI= UTC + 11 seconds +# 1 July 1972 00:00:00 (2287785600) TAI= UTC + 11 seconds +# ... +# +# If your system realizes the leap second by repeating 00:00:00 UTC twice +# (this is possible but not usual), then the advance to the next entry +# in the table must occur the second time that a time equivlent to +# 00:00:00 UTC is used. Thus, using the same example as above: +# +# ... +# 30 June 1972 23:59:59 (2287785599): TAI= UTC + 10 seconds +# 30 June 1972 23:59:60 (2287785600, first time): TAI= UTC + 10 seconds +# 1 July 1972 00:00:00 (2287785600,second time): TAI= UTC + 11 seconds +# ... +# +# in both cases the use of timestamps based on TAI produces a smooth +# time scale with no discontinuity in the time interval. +# +# This complexity would not be needed for negative leap seconds (if they +# are ever used). The UTC time would skip 23:59:59 and advance from +# 23:59:58 to 00:00:00 in that case. The TAI offset would decrease by +# 1 second at the same instant. This is a much easier situation to deal +# with, since the difficulty of unambiguously representing the epoch +# during the leap second does not arise. +# +# Questions or comments to: +# Judah Levine +# Time and Frequency Division +# NIST +# Boulder, Colorado +# jlevine(a)boulder.nist.gov +# +# Last Update of leap second values: 11 January 2012 +# +# The following line shows this last update date in NTP timestamp +# format. This is the date on which the most recent change to +# the leap second data was added to the file. This line can +# be identified by the unique pair of characters in the first two +# columns as shown below. +# +#$ 3535228800 +# +# The NTP timestamps are in units of seconds since the NTP epoch, +# which is 1900.0. The Modified Julian Day number corresponding +# to the NTP time stamp, X, can be computed as +# +# X/86400 + 15020 +# +# where the first term converts seconds to days and the second +# term adds the MJD corresponding to 1900.0. The integer portion +# of the result is the integer MJD for that day, and any remainder +# is the time of day, expressed as the fraction of the day since 0 +# hours UTC. The conversion from day fraction to seconds or to +# hours, minutes, and seconds may involve rounding or truncation, +# depending on the method used in the computation. +# +# The data in this file will be updated periodically as new leap +# seconds are announced. In addition to being entered on the line +# above, the update time (in NTP format) will be added to the basic +# file name leap-seconds to form the name leap-seconds.<NTP TIME>. +# In addition, the generic name leap-seconds.list will always point to +# the most recent version of the file. +# +# This update procedure will be performed only when a new leap second +# is announced. +# +# The following entry specifies the expiration date of the data +# in this file in units of seconds since 1900.0. This expiration date +# will be changed at least twice per year whether or not a new leap +# second is announced. These semi-annual changes will be made no +# later than 1 June and 1 December of each year to indicate what +# action (if any) is to be taken on 30 June and 31 December, +# respectively. (These are the customary effective dates for new +# leap seconds.) This expiration date will be identified by a +# unique pair of characters in columns 1 and 2 as shown below. +# In the unlikely event that a leap second is announced with an +# effective date other than 30 June or 31 December, then this +# file will be edited to include that leap second as soon as it is +# announced or at least one month before the effective date +# (whichever is later). +# If an announcement by the IERS specifies that no leap second is +# scheduled, then only the expiration date of the file will +# be advanced to show that the information in the file is still +# current -- the update time stamp, the data and the name of the file +# will not change. +# +# Updated through IERS Bulletin C46 +# File expires on: 28 June 2014 +# +#@ 3612902400 +# +2272060800 10 # 1 Jan 1972 +2287785600 11 # 1 Jul 1972 +2303683200 12 # 1 Jan 1973 +2335219200 13 # 1 Jan 1974 +2366755200 14 # 1 Jan 1975 +2398291200 15 # 1 Jan 1976 +2429913600 16 # 1 Jan 1977 +2461449600 17 # 1 Jan 1978 +2492985600 18 # 1 Jan 1979 +2524521600 19 # 1 Jan 1980 +2571782400 20 # 1 Jul 1981 +2603318400 21 # 1 Jul 1982 +2634854400 22 # 1 Jul 1983 +2698012800 23 # 1 Jul 1985 +2776982400 24 # 1 Jan 1988 +2840140800 25 # 1 Jan 1990 +2871676800 26 # 1 Jan 1991 +2918937600 27 # 1 Jul 1992 +2950473600 28 # 1 Jul 1993 +2982009600 29 # 1 Jul 1994 +3029443200 30 # 1 Jan 1996 +3076704000 31 # 1 Jul 1997 +3124137600 32 # 1 Jan 1999 +3345062400 33 # 1 Jan 2006 +3439756800 34 # 1 Jan 2009 +3550089600 35 # 1 Jul 2012 +# +# the following special comment contains the +# hash value of the data in this file computed +# use the secure hash algorithm as specified +# by FIPS 180-1. See the files in ~/pub/sha for +# the details of how this hash value is +# computed. Note that the hash computation +# ignores comments and whitespace characters +# in data lines. It includes the NTP values +# of both the last modification time and the +# expiration time of the file, but not the +# white space on those lines. +# the hash line is also ignored in the +# computation. +# +#h 1151a8f e85a5069 9000fcdb 3d5e5365 1d505b37 diff --git a/leapseconds b/leapseconds deleted file mode 100644 index 5b5c70e..0000000 --- a/leapseconds +++ /dev/null @@ -1,100 +0,0 @@ -# <pre> -# This file is in the public domain, so clarified as of -# 2009-05-17 by Arthur David Olson. - -# Allowance for leapseconds added to each timezone file. - -# The International Earth Rotation Service periodically uses leap seconds -# to keep UTC to within 0.9 s of UT1 -# (which measures the true angular orientation of the earth in space); see -# Terry J Quinn, The BIPM and the accurate measure of time, -# Proc IEEE 79, 7 (July 1991), 894-905. -# There were no leap seconds before 1972, because the official mechanism -# accounting for the discrepancy between atomic time and the earth's rotation -# did not exist until the early 1970s. - -# The correction (+ or -) is made at the given time, so lines -# will typically look like: -# Leap YEAR MON DAY 23:59:60 + R/S -# or -# Leap YEAR MON DAY 23:59:59 - R/S - -# If the leapsecond is Rolling (R) the given time is local time -# If the leapsecond is Stationary (S) the given time is UTC - -# Leap YEAR MONTH DAY HH:MM:SS CORR R/S -Leap 1972 Jun 30 23:59:60 + S -Leap 1972 Dec 31 23:59:60 + S -Leap 1973 Dec 31 23:59:60 + S -Leap 1974 Dec 31 23:59:60 + S -Leap 1975 Dec 31 23:59:60 + S -Leap 1976 Dec 31 23:59:60 + S -Leap 1977 Dec 31 23:59:60 + S -Leap 1978 Dec 31 23:59:60 + S -Leap 1979 Dec 31 23:59:60 + S -Leap 1981 Jun 30 23:59:60 + S -Leap 1982 Jun 30 23:59:60 + S -Leap 1983 Jun 30 23:59:60 + S -Leap 1985 Jun 30 23:59:60 + S -Leap 1987 Dec 31 23:59:60 + S -Leap 1989 Dec 31 23:59:60 + S -Leap 1990 Dec 31 23:59:60 + S -Leap 1992 Jun 30 23:59:60 + S -Leap 1993 Jun 30 23:59:60 + S -Leap 1994 Jun 30 23:59:60 + S -Leap 1995 Dec 31 23:59:60 + S -Leap 1997 Jun 30 23:59:60 + S -Leap 1998 Dec 31 23:59:60 + S -Leap 2005 Dec 31 23:59:60 + S -Leap 2008 Dec 31 23:59:60 + S -Leap 2012 Jun 30 23:59:60 + S - -# INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) -# -# SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE -# -# -# SERVICE DE LA ROTATION TERRESTRE -# OBSERVATOIRE DE PARIS -# 61, Av. de l'Observatoire 75014 PARIS (France) -# Tel. : 33 (0) 1 40 51 22 26 -# FAX : 33 (0) 1 40 51 22 91 -# e-mail : (E-Mail Removed) -# http://hpiers.obspm.fr/eop-pc -# -# Paris, 5 January 2012 -# -# -# Bulletin C 43 -# -# To authorities responsible -# for the measurement and -# distribution of time -# -# -# UTC TIME STEP -# on the 1st of July 2012 -# -# -# A positive leap second will be introduced at the end of June 2012. -# The sequence of dates of the UTC second markers will be: -# -# 2012 June 30, 23h 59m 59s -# 2012 June 30, 23h 59m 60s -# 2012 July 1, 0h 0m 0s -# -# The difference between UTC and the International Atomic Time TAI is: -# -# from 2009 January 1, 0h UTC, to 2012 July 1 0h UTC : UTC-TAI = - 34s -# from 2012 July 1, 0h UTC, until further notice : UTC-TAI = - 35s -# -# Leap seconds can be introduced in UTC at the end of the months of December -# or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every -# six months, either to announce a time step in UTC or to confirm that there -# will be no time step at the next possible date. -# -# -# Daniel GAMBIS -# Head -# Earth Orientation Center of IERS -# Observatoire de Paris, France diff --git a/leapseconds.awk b/leapseconds.awk new file mode 100644 index 0000000..732db99 --- /dev/null +++ b/leapseconds.awk @@ -0,0 +1,68 @@ +# Generate the 'leapseconds' file from 'leap-seconds.list'. + +# This file is in the public domain. + +BEGIN { + printf "%s", "\ +# Allowance for leapseconds added to each timezone file.\n\ +\n\ +# This file is in the public domain.\n\ +\n\ +# This file is generated automatically from the data in the public-domain\n\ +# leap-seconds.list file available from most NIST time servers.\n\ +# If the URL <ftp://time.nist.gov/pub/leap-seconds.list> does not work,\n\ +# you should be able to pick up leap-seconds.list from a secondary NIST server.\n\ +# For more about leap-seconds.list, please see\n\ +# The NTP Timescale and Leap Seconds\n\ +# <http://www.eecis.udel.edu/~mills/leap.html>.\n\ +\n\ +# The International Earth Rotation Service periodically uses leap seconds\n\ +# to keep UTC to within 0.9 s of UT1\n\ +# (which measures the true angular orientation of the earth in space); see\n\ +# Terry J Quinn, The BIPM and the accurate measure of time,\n\ +# Proc IEEE 79, 7 (July 1991), 894-905 <http://dx.doi.org/10.1109/5.84965>.\n\ +# There were no leap seconds before 1972, because the official mechanism\n\ +# accounting for the discrepancy between atomic time and the earth's rotation\n\ +# did not exist until the early 1970s.\n\ +\n\ +# The correction (+ or -) is made at the given time, so lines\n\ +# will typically look like:\n\ +# Leap YEAR MON DAY 23:59:60 + R/S\n\ +# or\n\ +# Leap YEAR MON DAY 23:59:59 - R/S\n\ +\n\ +# If the leapsecond is Rolling (R) the given time is local time.\n\ +# If the leapsecond is Stationary (S) the given time is UTC.\n\ +\n\ +# Leap YEAR MONTH DAY HH:MM:SS CORR R/S\n\ +" +} + +/^ *$/ { next } +/^#/ { next } + +{ + NTP_timestamp = $1 + TAI_minus_UTC = $2 + hash_mark = $3 + one = $4 + month = $5 + year = $6 + if (old_TAI_minus_UTC) { + if (old_TAI_minus_UTC < TAI_minus_UTC) { + sign = "23:59:60\t+" + } else { + sign = "23:59:59\t-" + } + if (month == "Jan") { + year--; + month = "Dec"; + day = 31 + } else if (month == "Jul") { + month = "Jun"; + day = 30 + } + printf "Leap\t%s\t%s\t%s\t%s\tS\n", year, month, day, sign + } + old_TAI_minus_UTC = TAI_minus_UTC +} -- 1.8.1.2

2 1

Proposal regarding tz DB and leap second updates
by Martin Burnicki Aug. 13, 2013

Aug. 13, 2013

Hi everybody, here are some thoughts about ways to make timekeeping simpler, especially with regards to DST, and leap seconds. Some time ago there was a discussion on the tz mailing list about frequently changing DST dates in Morocco, and that the Moroc government determines the beginning and end of DST only a very short period before the changes are to come into effect. A major problem is the short time period admins have available to deploy tz data base updates to machines in a mixed environment e.g. consisting of several Unix flavors, and Windows systems. I know Windows systems don't use the tz DB directly, but unlike older Windows version which could only provide DST information for the current year, current Windows version can at least provide DST settings for several years in their registry, and I could imagine some MS engineer has written a script which generates those registry settings from the tz DB. ;-) Updates of those registry settings are usually deployed as Windows patches. AFAIK even for Unix systems the tz DB updates are usually deployed as software updates, e.g. updated .rpm or .deb packages for Linux. So whenever there's a change in the DST specs for some country, a server admin responsible for different types of machines has to wait until all manufacturers or distributors of all the OS types and versions he is running on his machines have become aware of a tz DB update, and have provided software update packages for all their systems, before all machines can be updated consistently, each system type using its own update procedure. This may not be a big deal for users in the United States, or in Europe, where DST rules are changing only very rarely. If you don't install tz database updates then there's a good chance everything keeps working fine since no DST rules have changed. However, for people in Morocco, or Israel, or some other countries it seems to be quite a challenge to keep everything up to date, if there are changes once every year. We at Meinberg are manufacturing NTP time servers, and there are often requests from customers to use NTP to send local time to the clients. Of course this is no reliable solution and caused many sorts of other problems which are not obvious at the first glance. However, this shows the importance for a way to simplify tz DB updates. My proposal is to use some sort of network protocol to deploy the contents of the tz DB, either for a single time zone used on a system, or even for all time zones supported by the tz database. In my opinion this is similar to DNS or DHCP, or even NTP services. So a machine could simply run a TZ client daemon which periodically contacts a TZ server to check if there is an update available, and download the updated data if this is the case. A mechanism like the serial numbers used for DNS zone transfers could be used to do this. Of course the tz information must be deployed in a secure way, but this is a common requirement for all kind of network services today, using crypto mechanisms, etc. This would also simplify the update of tz data in embedded systems which often don't see any software updates anymore after they have been put into operation. Another important thing which could be implemented in the same protocol is handling of leap second information. I don't want to restart the discussion whether leap seconds are useful and required, or not, but the following suggestions can help to simplify handling of future leap seconds, if they should occur, and they don't hurt but help to handle historic leap seconds, if required to evaluate archived data, etc. Actually the NIST provides a leap second file providing current and historic leap second information. This file can directly be handled and evaluated by the standard NTP daemon. There are plans to implement this also in the open source PTP daemon, since PTP by default uses TAI for the timestamps in the network packets, and a leap second file is a good resource to convert between TAI and UTC. I know the tz DB also includes a leap second file, which is used for the "right" timezones. As far as I know this file provides similar information as the NIST file but has a slightly different format. My proposal is to change the TZ code and DB in a first step so that they also use the NIST leap second file format. I'm not aware of any operating system which uses the "right" timezones by default now, but as far as I can see such modification can be done consistently and transparently for the users, since both the tz code and the file can be updated consistently. So there should be no problems for folks who use the "right" timezones. Many types of hardware refclocks used to set up stratum-1 NTP servers don't provide the NTP daemon with leap second warnings, so those NTP servers often have to rely on a leap second file which needs to be updated if a leap second has been scheduled. Usually there are about 6 months time to do so. Also future versions of the PTP daemon will have this requirement. So if the same leap second file format was used for all applications then the same file could be shared, and for now, it could be updated within any tz database update. If in the future there should be a network protocol which could be used to deploy tz updates, then the same protocol could also be used to update the leap second file, if required, and life could become much easier for many admins. ;-) Any comments are welcome. [I'm also going to send this to the leapsecond mailing list, even though some folks may be subscribed on both lists] Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany

6 5

[PATCH] Remove attempt to support floating-point time_t.
by Paul Eggert Aug. 12, 2013

Aug. 12, 2013

Here's a proposed patch to remove the tz code's attempt to support floating-point time_t. This has the benefit of simplifying the code and making maintenance easier. Comments welcome (particularly if you know of any real systems that have floating-point time_t!). I've pushed this to the experimental github repository. ----- It wasn't tested and probably never worked, no platform used it, and the latest POSIX no longer allows it. * Makefile (typecheck): Don't check time_t being 'double'. * Theory: Document the change. * difftime.c (difftime): * localtime.c (differ_by_repeat, tzload, timesub, time2sub): * private.h (time_t_min, time_t_max): * zdump.c (absolute_min_time, absolute_max_time, tformat): Don't try to support floating-point time_t. * localtime.c, private.h, zdump.c: Don't include float.h. * localtime.c (truncate_time, double_to_time): * private.h (TYPE_INTEGRAL): * zdump.c (checkabsolutes): Remove; no longer needed. All uses removed. * zdump.8 (LIMITATIONS): Remove discussion of floating-point time_t. --- Makefile | 3 +-- Theory | 9 ++++----- difftime.c | 10 +--------- localtime.c | 62 ++++++------------------------------------------------------- private.h | 28 ++-------------------------- zdump.8 | 7 ------- zdump.c | 37 ++---------------------------------- 7 files changed, 16 insertions(+), 140 deletions(-) diff --git a/Makefile b/Makefile index 8b033a6..db7f56e 100644 --- a/Makefile +++ b/Makefile @@ -121,7 +121,6 @@ LDLIBS= # -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 -# -DTIME_T_FLOATING=1 if your time_t (or time_tz) is floating point # -Dtime_tz=\"T\" to use T as the time_t type, rather than the system time_t # -DTZ_DOMAIN=\"foo\" to use "foo" for gettext domain name; default is "tz" # -TTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory; @@ -541,7 +540,7 @@ tzdata$(VERSION).tar.gz.asc: tzdata$(VERSION).tar.gz typecheck: make clean - for i in "long long" unsigned double; \ + for i in "long long" unsigned; \ do \ make CFLAGS="-DTYPECHECK -D__time_t_defined -D_TIME_T \"-Dtime_t=$$i\"" ; \ ./zdump -v Europe/Rome ; \ diff --git a/Theory b/Theory index 1b5374a..b4bd4c2 100644 --- a/Theory +++ b/Theory @@ -104,11 +104,10 @@ POSIX has the following properties and limitations. new implementations these days typically use a signed 64-bit integer. Unsigned 32-bit integers are used on one or two platforms, and 36-bit integers are also used occasionally. - Although POSIX.1-2013 requires time_t to be an integer type, - earlier POSIX versions also allowed time_t to be a floating-point type. - No known platforms have a floating-point time_t and although - the tz code attempts to support floating-point time_t this has not - been tested and will probably be removed at some point. + Although earlier POSIX versions allowed time_t to be a + floating-point type, this was not supported by any practical + systems, and POSIX.1-2013 and the tz code both require time_t + to be an integer type. These are the extensions that have been made to the POSIX functions: diff --git a/difftime.c b/difftime.c index fcd18ce..449cdf0 100644 --- a/difftime.c +++ b/difftime.c @@ -5,7 +5,7 @@ /*LINTLIBRARY*/ -#include "private.h" /* for time_t, TYPE_INTEGRAL, and TYPE_SIGNED */ +#include "private.h" /* for time_t and TYPE_SIGNED */ double ATTRIBUTE_CONST difftime(const time_t time1, const time_t time0) @@ -16,15 +16,8 @@ difftime(const time_t time1, const time_t time0) */ if (sizeof (double) > sizeof (time_t)) return (double) time1 - (double) time0; - if (!TYPE_INTEGRAL(time_t)) { - /* - ** time_t is floating. - */ - return time1 - time0; - } if (!TYPE_SIGNED(time_t)) { /* - ** time_t is integral and unsigned. ** The difference of two unsigned values can't overflow ** if the minuend is greater than or equal to the subtrahend. */ @@ -33,7 +26,6 @@ difftime(const time_t time1, const time_t time0) else return -(double) (time0 - time1); } /* - ** time_t is integral and signed. ** Handle cases where both time1 and time0 have the same sign ** (meaning that their difference cannot overflow). */ diff --git a/localtime.c b/localtime.c index 9600901..5312ad9 100644 --- a/localtime.c +++ b/localtime.c @@ -13,7 +13,6 @@ #include "private.h" #include "tzfile.h" #include "fcntl.h" -#include "float.h" /* for FLT_MAX and DBL_MAX */ #ifndef TZ_ABBR_MAX_LEN #define TZ_ABBR_MAX_LEN 16 @@ -318,9 +317,8 @@ settzname(void) static int differ_by_repeat(const time_t t1, const time_t t0) { - if (TYPE_INTEGRAL(time_t) && - TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) - return 0; + if (TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) + return 0; return t1 - t0 == SECSPERREPEAT; } @@ -527,9 +525,9 @@ tzload(register const char *name, register struct state *const sp, for (i = 0; i < nread; ++i) up->buf[i] = p[i]; /* - ** If this is a narrow integer time_t system, we're done. + ** If this is a narrow time_t system, we're done. */ - if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t)) + if (stored >= (int) sizeof(time_t)) break; } if (doextend && nread > 2 && @@ -1254,35 +1252,6 @@ tzset(void) settzname(); } -/* Return T with any fractional part discarded. */ -static time_t -truncate_time(time_t t) -{ - /* - ** If time_t is floating-point, convert it to integer and - ** back; this discards the fraction. Avoid using <math.h> - ** functions, as we don't want to depend on <math.h>. Use <, - ** not <=, when comparing against *_MIN and *_MAX values, as - ** this avoids undefined behavior when, for example, - ** INTMAX_MAX is converted to a larger time_t value before it - ** is compared. - ** - ** On all platforms that we know of (1) it is safe to compare - ** INTMAX_MIN and INTMAX_MAX to floating-point values without - ** worrying about undefined behavior due to floating-point - ** overflow on conversion, and (2) any time_t value outside - ** intmax_t range is an integer so we can simply return it. - ** We know of no simple, portable way to check these assumptions. - ** If you know of a counterexample platform, please report a bug. - */ - if (!TYPE_INTEGRAL(time_t) && INTMAX_MIN < t && t < INTMAX_MAX) { - intmax_t i = t; - return i; - } - - return t; -} - /* ** The easy way to behave "as if no library function calls" localtime ** is to not call it--so we drop its guts into "localsub", which can be @@ -1318,8 +1287,7 @@ localsub(const time_t *const timep, const int_fast32_t offset, seconds = sp->ats[0] - t; else seconds = t - sp->ats[sp->timecnt - 1]; --seconds; - years = (truncate_time (seconds / SECSPERREPEAT + 1) - * YEARSPERREPEAT); + years = (seconds / SECSPERREPEAT + 1) * YEARSPERREPEAT; seconds = years * AVGSECSPERYEAR; if (t < sp->ats[0]) newt += seconds; @@ -1457,18 +1425,6 @@ offtime(const time_t *const timep, const long offset) #endif /* defined STD_INSPIRED */ /* -** Convert T to time_t, truncating toward zero if time_t is integral. -** On most platforms, double_to_time(0.5) returns 0; the exceptions are -** the rare platforms where time_t is floating. -*/ - -static time_t -double_to_time(double t) -{ - return t; -} - -/* ** Return the number of leap years through the end of the given year ** where, to make the math easy, the answer for year zero is defined as zero. */ @@ -1549,9 +1505,8 @@ timesub(const time_t *const timep, const int_fast32_t offset, } { register int_fast32_t seconds; - register time_t half_second = double_to_time(0.5); - seconds = tdays * SECSPERDAY + half_second; + seconds = tdays * SECSPERDAY; tdays = seconds / SECSPERDAY; rem += seconds - tdays * SECSPERDAY; } @@ -1811,11 +1766,6 @@ time2sub(struct tm *const tmp, if (!TYPE_SIGNED(time_t)) { lo = 0; hi = lo - 1; - } else if (!TYPE_INTEGRAL(time_t)) { - if (sizeof(time_t) > sizeof(float)) - hi = (time_t) DBL_MAX; - else hi = (time_t) FLT_MAX; - lo = -hi; } else { lo = 1; for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) diff --git a/private.h b/private.h index 5f4384e..8c1cda7 100644 --- a/private.h +++ b/private.h @@ -74,7 +74,6 @@ #include "sys/types.h" /* for time_t */ #include "stdio.h" #include "errno.h" -#include "float.h" /* for FLT_MAX and DBL_MAX */ #include "string.h" #include "limits.h" /* for CHAR_BIT et al. */ #include "time.h" @@ -318,37 +317,14 @@ const char * scheck(const char * string, const char * format); /* The minimum and maximum finite time values. */ static time_t const time_t_min = - ((time_t) 0.5 == 0.5 - ? (sizeof (time_t) == sizeof (float) ? (time_t) -FLT_MAX - : sizeof (time_t) == sizeof (double) ? (time_t) -DBL_MAX - : sizeof (time_t) == sizeof (long double) ? (time_t) -LDBL_MAX - : 0) -#ifndef TIME_T_FLOATING - : (time_t) -1 < 0 + (TYPE_SIGNED(time_t) ? (time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1) -#endif : 0); static time_t const time_t_max = - ((time_t) 0.5 == 0.5 - ? (sizeof (time_t) == sizeof (float) ? (time_t) FLT_MAX - : sizeof (time_t) == sizeof (double) ? (time_t) DBL_MAX - : sizeof (time_t) == sizeof (long double) ? (time_t) LDBL_MAX - : -1) -#ifndef TIME_T_FLOATING - : (time_t) -1 < 0 + (TYPE_SIGNED(time_t) ? - (~ 0 < 0) - ((time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1)) -#endif : -1); -/* -** Since the definition of TYPE_INTEGRAL contains floating point numbers, -** it cannot be used in preprocessor directives. -*/ - -#ifndef TYPE_INTEGRAL -#define TYPE_INTEGRAL(type) (((type) 0.5) != 0.5) -#endif /* !defined TYPE_INTEGRAL */ - #ifndef INT_STRLEN_MAXIMUM /* ** 302 / 1000 is log10(2.0) rounded up. diff --git a/zdump.8 b/zdump.8 index f253e81..af3277d 100644 --- a/zdump.8 +++ b/zdump.8 @@ -57,13 +57,6 @@ the program cuts off verbose output near the starts of the years \-500 and 2500. Cut off verbose output at the start of the given time(s), given in decimal seconds since 1970-01-01 00:00:00 UTC. .SH LIMITATIONS -The -.B \-v -and -.B \-V -options may not be used on systems with floating-point time_t values -that are neither float nor double. -.PP Time discontinuities are found by sampling the results returned by localtime at twelve-hour intervals. This works in all real-world cases; diff --git a/zdump.c b/zdump.c index be0a496..788020a 100644 --- a/zdump.c +++ b/zdump.c @@ -23,7 +23,6 @@ #include "sys/types.h" /* for time_t */ #include "time.h" /* for struct tm */ #include "stdlib.h" /* for exit, malloc, atoi */ -#include "float.h" /* for FLT_MAX and DBL_MAX */ #include "limits.h" /* for CHAR_BIT, LLONG_MAX */ #include "ctype.h" /* for isalpha et al. */ #ifndef isascii @@ -193,26 +192,12 @@ extern char * tzname[2]; /* The minimum and maximum finite time values. */ static time_t const absolute_min_time = - ((time_t) 0.5 == 0.5 - ? (sizeof (time_t) == sizeof (float) ? (time_t) -FLT_MAX - : sizeof (time_t) == sizeof (double) ? (time_t) -DBL_MAX - : sizeof (time_t) == sizeof (long double) ? (time_t) -LDBL_MAX - : 0) -#ifndef TIME_T_FLOATING - : (time_t) -1 < 0 + ((time_t) -1 < 0 ? (time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1) -#endif : 0); static time_t const absolute_max_time = - ((time_t) 0.5 == 0.5 - ? (sizeof (time_t) == sizeof (float) ? (time_t) FLT_MAX - : sizeof (time_t) == sizeof (double) ? (time_t) DBL_MAX - : sizeof (time_t) == sizeof (long double) ? (time_t) LDBL_MAX - : -1) -#ifndef TIME_T_FLOATING - : (time_t) -1 < 0 + ((time_t) -1 < 0 ? - (~ 0 < 0) - ((time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1)) -#endif : -1); static size_t longest; static char * progname; @@ -223,7 +208,6 @@ static void abbrok(const char * abbrp, const char * zone); static intmax_t delta(struct tm * newp, struct tm * oldp) ATTRIBUTE_PURE; static void dumptime(const struct tm * tmp); static time_t hunt(char * name, time_t lot, time_t hit); -static void checkabsolutes(void); static void show(char * zone, time_t t, int v); static const char * tformat(void); static time_t yeartot(intmax_t y) ATTRIBUTE_PURE; @@ -383,7 +367,6 @@ main(int argc, char *argv[]) exit(EXIT_FAILURE); } } - checkabsolutes(); if (cutarg != NULL || cuttimes == NULL) { cutlotime = yeartot(cutloyear); cuthitime = yeartot(cuthiyear); @@ -504,17 +487,6 @@ main(int argc, char *argv[]) return EXIT_FAILURE; } -static void -checkabsolutes(void) -{ - if (absolute_max_time < absolute_min_time) { - (void) fprintf(stderr, -_("%s: use of -v on system with floating time_t other than float or double\n"), - progname); - exit(EXIT_FAILURE); - } -} - static time_t yeartot(const intmax_t y) { @@ -666,11 +638,6 @@ abbr(struct tm *tmp) static const char * tformat(void) { - if (0.5 == (time_t) 0.5) { /* floating */ - if (sizeof (time_t) > sizeof (double)) - return "%Lg"; - return "%g"; - } if (0 > (time_t) -1) { /* signed */ if (sizeof (time_t) == sizeof (intmax_t)) return "%"PRIdMAX; -- 1.8.1.2

1 0

[PATCH] Use symbolic links to deduplicate installed files.
by Paul Eggert Aug. 11, 2013

Aug. 11, 2013

* 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. --- Makefile | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/Makefile b/Makefile index 3659378..8b033a6 100644 --- a/Makefile +++ b/Makefile @@ -51,7 +51,8 @@ TOPDIR= /usr/local # (and subdirectories). # Use an absolute path name for TZDIR unless you're just testing the software. -TZDIR= $(TOPDIR)/etc/zoneinfo +TZDIR_BASENAME= zoneinfo +TZDIR= $(TOPDIR)/etc/$(TZDIR_BASENAME) # Types to try, as an alternative to time_t. int64_t should be first. TIME_T_ALTERNATIVES= int64_t int32_t uint32_t uint64_t @@ -390,15 +391,21 @@ right_only: zic leapseconds $(TDATA) # Therefore, the other two directories are now siblings of $(TZDIR). # You must replace all of $(TZDIR) to switch from not using leap seconds # to using them, or vice versa. -other_two: zic leapseconds $(TDATA) +right_posix: right_only + rm -fr $(TZDIR)-leaps + ln -s $(TZDIR_BASENAME) $(TZDIR)-leaps || \ + $(ZIC) -y $(YEARISTYPE) \ + -d $(TZDIR)-leaps -L leapseconds $(TDATA) $(ZIC) -y $(YEARISTYPE) -d $(TZDIR)-posix -L /dev/null $(TDATA) + +posix_right: posix_only + rm -fr $(TZDIR)-posix + ln -s $(TZDIR_BASENAME) $(TZDIR)-posix || \ + $(ZIC) -y $(YEARISTYPE) \ + -d $(TZDIR)-posix -L /dev/null $(TDATA) $(ZIC) -y $(YEARISTYPE) \ -d $(TZDIR)-leaps -L leapseconds $(TDATA) -posix_right: posix_only other_two - -right_posix: right_only other_two - zones: $(REDO) $(TZLIB): $(LIBOBJS) -- 1.8.1.2

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