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Looking for a way to cut down binary zoneinfo size. Does anyone have the way to?
by Viktor Sergiienko May 19, 2017

May 19, 2017

Hello, I'm developing for a pretty small-sized embedded system, and 2.9M of binaries is a bit too much for us. The system never uses a date before 2007. I estimate I can slim it down too 500K by cutting down the old data. 1. I made a script to cut down the source data: all the rules and all the zonelines before 2001. Compiling this data, I get a lot of errors like: > "northamerica", line 2537: %s in ruleless zone > "northamerica", line 2618: unruly zone because some zones are left without rules, but with %s format in them. 2. I tried to modify zic itself, but apparently understanding it will take me days. Just setting min_year to 2001 results in bunch of > can't determine time zone abbreviation to use just after until time Does anyone have a ready solution? Thanks!

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[PROPOSED 1/2] Rename ‘lint’ to ‘GCC_LINT’
by Paul Eggert May 18, 2017

May 18, 2017

* Makefile (GCC_DEBUG_FLAGS): * private.h (INITIALIZE): Rename ‘lint’ to ‘GCC_LINT’, as the macro is intended for GCC, not for traditional ‘lint’. --- Makefile | 2 +- private.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index e7c6ac0..bcfdcb2 100644 --- a/Makefile +++ b/Makefile @@ -159,7 +159,7 @@ LDLIBS= # (or some other number) to set the maximum time zone abbreviation length # that zic will accept without a warning (the default is 6) # $(GCC_DEBUG_FLAGS) if you are using recent GCC and want lots of checking -GCC_DEBUG_FLAGS = -Dlint -g3 -O3 -fno-common -fstrict-aliasing \ +GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common -fstrict-aliasing \ -Wall -Wextra \ -Wbad-function-cast -Wcast-align -Wdate-time \ -Wdeclaration-after-statement \ diff --git a/private.h b/private.h index e9eb211..6886185 100644 --- a/private.h +++ b/private.h @@ -566,7 +566,7 @@ static time_t const time_t_max = MAXVAL(time_t, TYPE_BIT(time_t)); ** INITIALIZE(x) */ -#ifdef lint +#ifdef GCC_LINT # define INITIALIZE(x) ((x) = 0) #else # define INITIALIZE(x) -- 2.9.4

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Morocco changes May 27th 2017 instead of May 21th
by Info - avisched.com May 17, 2017

May 17, 2017

Morocco is about to switch on May 27th back to UTC from +1. The current release doesn't reflect that (May 21st). Is there any update planned before the actual transition? Many thanks! Martin

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Asia/Harbin, Asia/Chongqing and Asia/Kashgar
by Phake Nick May 13, 2017

May 13, 2017

iirc, according to past conversation on the mailing list, the reason why these timezones that are not in use for many years already still exists in tz database is because of legacy reason, however given that Asia/Ishigaki were deleted from this database in 1999 when it's found to be not in use, is there any reason preventing the same to be done to Asia/Harbin, Asia/Chongqing, and Asia/Kashgar?

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gcc 8 demanded patch (from NetBSD)
by Robert Elz May 11, 2017

May 11, 2017

The following patch was recently added to NetBSD, to appease GCC 8 (apparently) ... "hit" is a bool, and it seems gcc 8 does not like ++ operators applied to one of those. (deleted parts of the diff which just showed the version ID string being updated...) kre Index: src/lib/libc/time/localtime.c diff -u src/lib/libc/time/localtime.c:1.106 src/lib/libc/time/localtime.c:1.107 --- src/lib/libc/time/localtime.c:1.106 Sat Mar 11 18:23:14 2017 +++ src/lib/libc/time/localtime.c Tue May 9 02:30:49 2017 @@ -1716,7 +1716,7 @@ timesub(const time_t *timep, int_fast32_ sp->lsis[i - 1].ls_trans + 1 && sp->lsis[i].ls_corr == sp->lsis[i - 1].ls_corr + 1) { - ++hit; + hit = true; --i; } }

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TZDEFRULESTRING is increasingly out-of-date
by Tom Lane May 7, 2017

May 7, 2017

Due to a script's unintended failure to supply a -p option to zic, I recently had my nose rubbed in the fact that localtime.c still has this as the fallback when the "posixrules" link can't be loaded: /* ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. ** We default to US rules as of 1999-08-17. ** POSIX 1003.1 section 8.1.1 says that the default DST rules are ** implementation dependent; for historical reasons, US rules are a ** common default. */ #ifndef TZDEFRULESTRING #define TZDEFRULESTRING ",M4.1.0,M10.5.0" #endif /* !defined TZDEFDST */ It's now over ten years since the US last followed those rules; isn't it time to update TZDEFRULESTRING to match current law? I can't really think of any situation where the current default would be of any value now. Apologies if this policy is being followed intentionally; but I couldn't find any discussion of the point by googling. regards, tom lane

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Potted history of timekeeping from the BBC
by John Haxby April 21, 2017

April 21, 2017

This is from a series of things that made the modern economy, it says on the web page: Tick tock: The importance of knowing the right time: http://www.bbc.co.uk/news/business-39129620 In one short page it manages to mention everything but DST :) and it includes a picture of Harrison No 1. (If you're ever near Greenwich I recommend visiting the Royal Observatory, taking the obligatory foot-in-both-hemispheres selfie and then going to look at the clocks.) >From the BBC web page though, I particularly noticed this: > Some financiers recently calculated it was worth spending $300m (£247m) drilling through mountains between Chicago and New York to lay fibre-optic cables in a slightly straighter line. That sped up communication between the two cities' exchanges by three milliseconds. jch

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Re: [tz] leapseconds.awk, LEAP directives and references
by Chris Woodbury April 21, 2017

April 21, 2017

In the course of reviewing the AWK script leapseconds.awk, I was disturbed by the fact that it (1) operated on the comments (probably not a good idea) in the NIST produced leap-seconds.list file rather than the NTP timestamp itself and (2) that it assumed that leap seconds would only occur in December and June. The regulation that governs leap seconds, ITU-R TF.460-6 <https://www.itu.int/rec/R-REC-TF.460-6-200202-I/>, actually allows leap seconds to occur at the end of any UTC month. Annex 1, Section 2: Leap Seconds 2.1 A positive or negative leap-second should be the last second of a UTC month, but first preference should be given to the end of December and June, and second preference to the end of March and September. I note, in the event of a (highly unlikely) negative leap second, the LEAP directive generated is for 23:59:59 which, in the case of a negative leap second, doesn't exist. I reviewed the C code and, it seems to me, the transaction added should actually be for the second before, 23:59:58, as the transaction itself causes 23:59:59 to be skippedaltogether. (Kinda hard to skip an event if you're in it.) I bring this up as I've alrady written the changes necessary but I want to verify the correctness of this last beforesubmitting them. Also, I've an AWK script that uses the IERS file Leap_Seconds.dat rather than the NIST leap-seconds.listfile. Leap_Seconds.dat is a straight list of leap-seconds. USNO MAIA also has straight list of leap-seconds in a different format. See URLs: <http://hpiers.obspm.fr/iers/bul/bulc/Leap_Seconds.dat> <http://maia.usno.navy.mil/ser7/leapsec.dat> Either of these would, particularly the IERS file as it has few but excellent comments, be a better source of leap-second information than the once removed NIST file leap-seconds.list; which is purposed for another task. Lastly, thanks to Dr. Eggert for including the reference I gave him to the AAPT Resource Letter that included Terry Quinn's article in the NIST Time and Frequency Division's PDF archive (1168). Anyone wanting to know about Time and Frequency Measurement might want to read the other articles as well as Dr. Quinn's. Another good, comprehensive article is "The leap second: its history and possible future" by R.A. Nelson, et al, from Metrogia Vol 38, pp. 509-529 (2001). PDF available (with permission) at: <https://www.cl.cam.ac.uk/~mgk25/time/metrologia-leapsecond.pdf>

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[PROPOSED] Use railway time for India from 1870-1941
by Paul Eggert April 20, 2017

April 20, 2017

From: Paul Eggert <eggert(a)Penguin.CS.UCLA.EDU> * NEWS: Document this. * asia (Asia/Yangon): Add 7 s to times from 1880 to 1920. (Asia/Kolkata): Switch from HMT to MMT in 1870, and from MMT to IST in 1906. --- NEWS | 11 +++++++++++ asia | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 64 insertions(+), 6 deletions(-) diff --git a/NEWS b/NEWS index f986cf6..ad099f4 100644 --- a/NEWS +++ b/NEWS @@ -1,5 +1,16 @@ News for the tz database +Unreleased, experimental changes + + Changes to past time stamps + + 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. + + Add 7 s to the UT offset in Asia/Yangon before 1920. + + Release 2017b - 2017-03-17 07:30:38 -0700 Briefly: Haiti has resumed DST. diff --git a/asia b/asia index 35774c6..f027071 100644 --- a/asia +++ b/asia @@ -258,9 +258,15 @@ Zone Asia/Brunei 7:39:40 - LMT 1926 Mar # Bandar Seri Begawan # Milne says 6:24:40 was the meridian of the time ball observatory at Rangoon. +# From Paul Eggert (2017-04-20): +# Page 27 of Reed & Low (cited for Asia/Kolkata) says "Rangoon local time is +# used upon the railways and telegraphs of Burma, and is 6h. 24m. 47s. ahead +# of Greenwich." This refers to the period before Burma's transition to +0630, +# a transition for which Shanks is the only source. + # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Yangon 6:24:40 - LMT 1880 # or Rangoon - 6:24:40 - RMT 1920 # Rangoon Mean Time? +Zone Asia/Yangon 6:24:47 - LMT 1880 # or Rangoon + 6:24:47 - RMT 1920 # Rangoon local time 6:30 - +0630 1942 May 9:00 - +09 1945 May 3 6:30 - +0630 @@ -887,14 +893,55 @@ Zone Asia/Dili 8:22:20 - LMT 1912 Jan 1 # local time in favor of Indian Standard Time.... Journalists called this # dispute the "Battle of the Clocks." It lasted nearly half a century. +# From Paul Eggert (2017-04-20): +# Good luck trying to nail down old timekeeping records in India. +# "... in the nineteenth century ... Madras Observatory took its magnetic +# measurements in Göttingen time, its meterological measurements on Madras +# (local) time, dropped its time ball on Greenwich (ocean navigator's) time, +# and distributed civil (local time)." -- Bartky IR. Selling the time: +# 19th-century timekeeping in america. Stanford U Press (2000), 247 note 19. +# "A more potent cause of resistance to the general adoption of the present +# standard time lies in the fact that it is Madras time. The citizen of +# Bombay, proud of being 'primus in Indis' and of Calcutta, equally proud of +# his city being the Capital of India, and - for a part of the year - the Seat +# of the Supreme Government, alike look down on Madras, and refuse to change +# the time they are using, for that of what they regard as a benighted +# Presidency; while Madras, having for long given the standard time to the +# rest of India, would resist the adoption of any other Indian standard in its +# place." -- Oldham RD. On Time in India: a suggestion for its improvement. +# Proceedings of the Asiatic Society of Bengal (April 1899), 49-55. +# +# "In 1870 ... Madras time - 'now used by the telegraph and regulated from the +# only government observatory' - was suggested as a standard railway time, +# first to be dopted on the Great Indian Peninsular Railway (GIPR).... +# Calcutta, Bombay, and Karachi, were to be allowed to continue with their +# local time for civil purposes." - Prasad R. Tracks of Change: Railways and +# Everyday Life in Colonial India. Cambridge University Press (2016), 145. +# +# Reed S, Low F. The Indian Year Book 1936-37. Bennett, Coleman, pp 27-8. +# https://archive.org/details/in.ernet.dli.2015.282212 +# This lists +052110 as Madras local time used in railways, and says that on +# 1906-01-01 railways and telegraphs in India switched to +0530. Some +# municipalities retained their former time, and the time in Calcutta +# continued to depend on whether you were at the railway station or at +# government offices. Government time was at +055320 (according to Shanks) or +# at +0554 (according to the Indian Year Book). Railway time is more +# appropriate for our purposes, as it was better documented, it is what we do +# elsewhere (e.g., Europe/London before 1880), and after 1906 it was +# consistent in the region now identified by Asia/Kolkata. So, use railway +# time for 1870-1941. Shanks is our only (and dubious) source for the +# 1941-1945 data. + # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Kolkata 5:53:28 - LMT 1880 # Kolkata - 5:53:20 - HMT 1941 Oct # Howrah Mean Time? - 6:30 - +0630 1942 May 15 +Zone Asia/Kolkata 5:53:28 - LMT 1854 Jun 28 # Kolkata + 5:53:20 - HMT 1870 # Howrah Mean Time? + 5:21:10 - MMT 1906 Jan 1 # Madras local time + 5:30 - IST 1941 Oct + 5:30 1:00 +0630 1942 May 15 5:30 - IST 1942 Sep 5:30 1:00 +0630 1945 Oct 15 5:30 - IST -# The following are like Asia/Kolkata: +# Since 1970 the following are like Asia/Kolkata: # Andaman Is # Lakshadweep (Laccadive, Minicoy and Amindivi Is) # Nicobar Is -- 2.9.3

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Mouradconstantine@icloud.com
by Mourad Constantine April 13, 2017

April 13, 2017

Sent from my iPhone

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