- tz - lists.iana.org

[PROPOSED] * tz-link.html: Link to Google Time Zone Data.
by Paul Eggert March 5, 2018

March 5, 2018

--- tz-link.html | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tz-link.html b/tz-link.html index 0fc4bc6..f3ac4ed 100644 --- a/tz-link.html +++ b/tz-link.html @@ -182,6 +182,8 @@ data yourself. System-specific instructions for installing the latest <code><abbr>tz</abbr></code> data have also been published for <a href="https://www.ibm.com/developerworks/aix/library/au-aix-olson-time-zone/index…"><abbr>AIX</abbr></a>, <a +href="https://play.google.com/store/apps/details?id=com.google.android.timezone.d…">Android</a>, +<a href="http://userguide.icu-project.org/datetime/timezone"><abbr title="International Components for Unicode">ICU</abbr></a>, <a href="https://developer.ibm.com/javasdk/support/dst/jtzu/"><abbr>IBM</abbr></a> -- 2.7.4

1 0

[PROPOSED] * australasia: Mention Pearce 2017 for Queensland.
by Paul Eggert Feb. 27, 2018

Feb. 27, 2018

--- australasia | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/australasia b/australasia index c7c0ea7..32ad61e 100644 --- a/australasia +++ b/australasia @@ -1086,6 +1086,13 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901 # South Australian time even though it's located in Western Australia. # Queensland + +# From Paul Eggert (2018-02-26): +# I lack access to the following source for Queensland DST: +# Pearce C. History of daylight saving time in Queensland. +# Queensland Hist J. 2017 Aug;23(6):389-403 +# https://search.informit.com.au/documentSummary;dn=994682348436426;res=IELHSS + # From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06): # # The state of QUEENSLAND.. [ Courtesy Qld. Dept Premier Econ&Trade Devel ] # # [ Dec 1990 ] -- 2.7.4

1 0

Converting cities to tz identifiers (tangent)
by John Hawkinson Feb. 26, 2018

Feb. 26, 2018

This is a bit of a rambling tangent, so sorry. I recently had to find tz zones for ~100 American cities, and the process did not go quite as smoothly as I had expected. I figured that a review of theory.html and tz-link.html would tell me the best way to do this, and it didn't really work out that way. The result was that I found myself just reading the "northamererica" file and knocking out the states that were unambiguous, and then checking the rest against timeanddate.com or time.is. It seems wrong that this appeared to be the easiest approach at this scale, so I wonder what others would suggest (with the benefit of hindsight). And then, in most cases, converting the zones via "backward" to the "US/Eastern" American political because doing so seemed more "stable." * I was expecting theory.html to give me a little more guidance on the "right" way to do this. As best as I can tell, the "right" (no pun intended) answer is that I should geolocate each city to longitude/latitude (using some unspecified resource, which seems fine), then use one of the datasets or tools at https://data.iana.org/time-zones/tz-link.html#boundaries to convert those locations to zones. This seemed a bit much. * I was also a little surprised to not find someone with a handy list of United States states and territory mappings to tz identifiers (for those cases where the state/territory/district uniquely mapped to a tzid). Other than the comments in "northamerica" (which are not quite as structured as one might like, but are pretty good). * Then I was faced with the question of what the most stable identifier to use was. For instance, take Boston, Massachusetts. I could record it as America/New_York, or as US/Eastern. For instance, at some point in the future, either Boston or New York might exit the Eastern time zone. Cases: Case 1: If that New York exited and Boston didn't, picking US/Eastern would clearly be the more stable choice. Case 2: And if Boston exited and New York didn't, it wouldn't matter which I chose, I'd have to update my mapping when Boston moved. Case 3: If New York and Boston both exited US/Eastern and went the same way, then America/New_York would be the better choice. Case 4: If New York and Boston both exited US/Eastern and did different things, it's not clear which is the better choice, but similar to Case 2. Lather rinse repeat for 50 states + some territories and DC. My conclusion was that in general, for most locations, the US/* ("backward") form seemed the better choice. (Both Massachusetts and Florida seem to have current proposals to depart US/Eastern and America/New_York.) * So, I'm curious if this anecdote triggers any reactions. Did I miss an obvious way to address this more simply? Is it horrible to have made use of third party websites that lack any sort of auditable authority but are probably correct anyhow. Is this just not a problem that people have to solve with any frequency? Does someone (Paul?) want to convince me that it's Wrong to use the "backward" zones, for the narrow (but common) case of United States of America cities? Thanks for any thoughts. --jhawk(a)mit.edu John Hawkinson

17 32

Need to update Kansas City, MO
by Kevin DeCapite Feb. 25, 2018

Feb. 25, 2018

I would like to propose a change to the database to account for Kansas City, Missouri, USA as having not observed DST between 1946 - 1965. Please see the source book referenced in the link (page 87 in the actual printed pages, standard PDF is the best way to view it): https://archive.org/details/time-changes-in-usa-1966 <https://archive.org/details/time-changes-in-usa-1966> I can also confirm the accuracy of at least this piece of information through testimony. What are the procedures for formally proposing, reviewing & accepting/rejecting such changes? Thank you. --- Kevin DeCapite kevin(a)decapite.net 562.355.8222

2 1

AP & WFLA-TV: Florida House OKs bill asking to skip Daylight Saving Time
by Vance, Frank Feb. 24, 2018

Feb. 24, 2018

http://wfla.com/2018/02/14/florida-house-oks-bill-asking-to-skip-daylight-s… "The [Florida] House voted 103-11 to approve the bill to ask Congress to let Florida remain in Daylight Saving Time all year, meaning while the rest of the Eastern United States sets their clocks back in the fall, Florida wouldn't." Regards, F

7 8

SGT abbreviation is missing from the IANA tz database
by Lu, Can Feb. 21, 2018

Feb. 21, 2018

Hi Paul, Hope you're well. By way of introduction, this is Can, working as a software developer in BAML. We noticed that Asia/Singapore had its SGT abbreviation dropped in tzdb 2017, and the reason being is that the zone abbreviation doesn't correspond to any real-world usage. But it's actually not entirely true, SGT is very commonly used in Singapore and it's also a standard abbreviation for Singapore time. Please refer to: https://en.wikipedia.org/wiki/List_of_time_zone_abbreviations and https://en.wikipedia.org/wiki/List_of_time_zone_abbreviations Wondering if it's possible to add SGT back to IANA db as I believe this change will cause breaks to other libraries rely on it. (We're using pytz for python development). I am happy to discuss and appreciate any thoughts you may have on it. Thanks, Can ---------------------------------------------------------------------- This message, and any attachments, is for the intended recipient(s) only, may contain information that is privileged, confidential and/or proprietary and subject to important terms and conditions available at http://www.bankofamerica.com/emaildisclaimer. If you are not the intended recipient, please delete this message.

4 4

[PROPOSED] Parallelize the main part of 'make to2050new.tzs'
by Paul Eggert Feb. 21, 2018

Feb. 21, 2018

This improves real-time performance of 'make -j4 to2050new.tzs' by a factor of about 3.5 (from 120 s to 34 s) on my old 4-core desktop, which runs Fedora 27 x86-64 atop an AMD Phenom II X4 910e. * Makefile (ZDS): New macro. ($(ZDS)): New rule. All targets are phony. ($(TZS_NEW)): Use it in a submake that is parallelized by GNU make -j. (check_links): Depend on tzdata.zi, fixing a dependency bug. * NEWS: Mention this. --- Makefile | 29 ++++++++++++++++++++--------- NEWS | 4 ++++ 2 files changed, 24 insertions(+), 9 deletions(-) diff --git a/Makefile b/Makefile index fc15c3e..835f34b 100644 --- a/Makefile +++ b/Makefile @@ -640,19 +640,29 @@ posix_packrat: zones: $(REDO) +# dummy.zd is not a real file; it is mentioned here only so that the +# top-level 'make' does not have a syntax error. +ZDS = dummy.zd +# Rule used only by submakes invoked by the $(TZS_NEW) rule. +# It is separate so that GNU 'make -j' can run instances in parallel. +$(ZDS): zdump + ./zdump -i -c $(TZS_YEAR) '$(wd)/'$$(expr $@ : '$.*$.zd') >$@ + $(TZS_NEW): tzdata.zi zdump zic - mkdir -p tzs.dir + rm -fr tzs.dir + mkdir tzs.dir $(zic) -d tzs.dir tzdata.zi $(AWK) '/^L/{print "Link\t" $$2 "\t" $$3}' \ tzdata.zi | LC_ALL=C sort >$@.out wd=`pwd` && \ - zones=`$(AWK) -v wd="$$wd" \ - '/^Z/{print wd "/tzs.dir/" $$2}' tzdata.zi \ - | LC_ALL=C sort` && \ - ./zdump -i -c $(TZS_YEAR) $$zones >>$@.out - sed 's,^TZ=".*tzs\.dir/,TZ=",' $@.out >$@.sed.out - rm -fr tzs.dir $@.out - mv $@.sed.out $@ + set x `$(AWK) '/^Z/{print "tzs.dir/" $$2 ".zd"}' tzdata.zi \ + | LC_ALL=C sort -t . -k 2,2` && \ + shift && \ + ZDS=$$* && \ + $(MAKE) wd="$$wd" TZS_YEAR=$(TZS_YEAR) ZDS="$$ZDS" $$ZDS && \ + sed 's,^TZ=".*tzs\.dir/,TZ=",' $$ZDS >>$@.out + rm -fr tzs.dir + mv $@.out $@ # If $(TZS) does not already exist (e.g., old-format tarballs), create it. # If it exists but 'make check_tzs' fails, a maintainer should inspect the @@ -730,7 +740,7 @@ check_sorted: backward backzone iso3166.tab zone.tab zone1970.tab $(AWK) '/^[^#]/ $(CHECK_CC_LIST)' zone1970.tab | \ LC_ALL=C sort -cu -check_links: checklinks.awk $(TDATA_TO_CHECK) +check_links: checklinks.awk $(TDATA_TO_CHECK) tzdata.zi $(AWK) -f checklinks.awk $(TDATA_TO_CHECK) $(AWK) -f checklinks.awk tzdata.zi @@ -964,3 +974,4 @@ zic.o: private.h tzfile.h version.h .PHONY: public right_only right_posix signatures signatures_version .PHONY: tarballs tarballs_version typecheck .PHONY: zonenames zones +.PHONY: $(ZDS) diff --git a/NEWS b/NEWS index 3d18e89..1d2827e 100644 --- a/NEWS +++ b/NEWS @@ -79,6 +79,10 @@ Unreleased, experimental changes already can use vanguard.zi; in this respect, current tzcode is bleeding-edge. + The Makefile should now be safe for parallelized builds, and 'make + -j to2050new.tzs' is now much faster on a multiprocoessor host + with GNU Make. + When built with -DSUPPRESS_TZDIR, the tzcode library no longer prepends TZDIR/ to file names that do not begin with '/'. This is not recommended for general use, due to its security implications. -- 2.14.3

1 0

timezone history of Uruguay
by Jeremie Bonjour Feb. 20, 2018

Feb. 20, 2018

I submitted this information because it is not correct on the iana. org website. Greetings! Source: http://www.armada.mil.uy/ContenidosPDFs/sohma/web/almanaque/almanaque_2018.… Army Force of Uruguay http://www.armada.mil.uy .:Armada Nacional - Marina de Uruguay:.<http://www.armada.mil.uy/> www.armada.mil.uy Embarcación demorada La Armada Nacional, a través del Centro Coordinador de Búsqueda y Rescate en el Mar (MRCC), está realizando la búsqueda de un pesquero ... Almanac 2018, page 38 [cid:4e5339c0-4b51-4184-b33a-ad63059bec3a] Saludos. Jeremie Bonjour (+598) 093 81 21 71

4 9

Sol 5000 for Opportunity
by Tim Parenti Feb. 18, 2018

Feb. 18, 2018

Today, 16 February 2018, at 01:26:20.092 UTC, it is 01:01:06 Coordinated Mars Time on Mars Sol Date 51235, which corresponds to midnight HLST (hybrid local solar time) at the beginning of mission sol 5000 for the Opportunity (MER-B) rover at its mission reference longitude. The sol will last, of course, for 24 hours 39 minutes 35.244 seconds, ending on 17 February 2018 at 02:05:55.336 UTC. Curiosity will observe its mission sol 2000 next month, reckoned in mean solar time at its landing site, from 2018-03-22 13:24:49.020 UTC to 2018-03-23 14:04:24.264 UTC. -- Tim Parenti

5 7

apply Portuguese decree of 1911-05-30
by Michael H Deckers Feb. 17, 2018

Feb. 17, 2018

The decree [http://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf] of 1911-05-30, mentioned for Europe/Lisbon prescribes time zone time scales for continental Portugal, Madeira, Azores, Cabo Verde, Guinea-Bissau, São Tomé, Angola, and Moçambique. It is currently not applied to all of these locations, and its article 5 is not correctly applied: " Art. 5.º Estas disposições entrarão em vigor no instante em que, segundo o artigo 2.º, começar o dia civil 1 de [j]aneiro de 1912, devendo então todos os relogios ser adeantados ou atrasados convenientemente, conforme as alineas seguintes:"... -- These dispositions shall enter into force at the instant at which, -- according to the 2nd article, the civil day January 1, 1912 begins, -- all clocks therefore having to be advanced or set back correspondingly, -- conforming with the following sections:.... (Article 2 specifies the various time zone time scales GMT + 00 h, GMT - 02 h, etc to be used in Portugal from 1912-01-01 onward.) The following proposals contain the necessary corrections. I have also tried to indicate exactly which data are implied by the source. I see this as a small step to make the tzdb data traceable to its sources, and thus to clarify the uncertainty of tzdb data (when they are estimated, or derived from less reliable sources). The format of these indications can certainly be improved. +# [pt 1911] decree https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf of 1911-05-30 # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Atlantic/Azores -1:42:40 - LMT 1884 # Ponta Delgada - -1:54:32 - HMT 1912-01-01 # Horta Mean Time +# [pt 1911] specifies UNTIL date, time & new GMTOFF: + -1:54:32 - HMT 1912-01-01 02:00u # Horta Mean Time -2:00 Port -02/-01 1942 Apr 25 22:00s # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Atlantic/Madeira -1:07:36 - LMT 1884 # Funchal - -1:07:36 - FMT 1912-01-01 # Funchal Mean Time +# [pt 1911] specifies UNTIL date, time & new GMTOFF: + -1:07:36 - FMT 1912-01-01 01:00u # Funchal Mean Time -1:00 Port -01/+00 1942 Apr 25 22:00s # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Lisbon -0:36:45 - LMT 1884 - -0:36:45 - LMT 1912 Jan 1 # Lisbon Mean Time +# [pt 1911] specifies UNTIL date, time & unrounded old (-00:36:44.68) and new GMTOFF: + -0:36:45 - LMT 1912 Jan 1 00:00u # Lisbon Mean Time 0:00 Port WE%sT 1966 Apr 3 2:00 The correction for Europe/Lisbon is an example where I think that Paul Eggert's proposal for GMTOFF values with fractional seconds would be helpful. [pt 1911] specifies Cabo Verde to use UT - 02 h since 1912-01-01 02:00Z. Currently, tzdb has a switch to UT - 02 h in 1907 without source (Shanks by default). This switch would precede the one in [pt 1911] which appears to be unlikely (admittedly, we know from Guernsey on 1913-06-18 that such conclusions may be wrong). # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Atlantic/Cape_Verde -1:34:04 - LMT 1907 # Praia +# [pt 1911] specifies UNTIL date, time & new GMTOFF: +# Ignore [Shanks] specifying UNTIL year 1907, no date, no time. +Zone Atlantic/Cape_Verde -1:34:04 - LMT 1912-01-01 02:00u # Praia -2:00 - -02 1942 Sep # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Africa/Bissau -1:02:20 - LMT 1912 Jan 1 +# [pt 1911] specifies UNTIL date, time & new GMTOFF: +Zone Africa/Bissau -1:02:20 - LMT 1912 Jan 1 01:00u # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Africa/Sao_Tome 0:26:56 - LMT 1884 - -0:36:32 - LMT 1912 # Lisbon Mean Time +# [pt 1911] specifies UNTIL date, time & new GMTOFF: + -0:36:32 - LMT 1912-01-01 00:00u # Lisbon Mean Time 0:00 - GMT 2018 Jan 1 01:00 Note that Lisbon Mean Time as in [pt 1911] and in [Milne 1899] differs from the GMTOFF given here for it (from Shanks?). # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Macau 7:34:20 - LMT 1912 Jan 1 +# [pt 1911] specifies UNTIL date, time & new GMTOFF: +Zone Asia/Macau 7:34:20 - LMT 1911-12-31 16:00u 8:00 Macau C%sT In backzone: # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Africa/Luanda 0:52:56 - LMT 1892 - 0:52:04 - LMT 1912 Jan 1 +# [pt 1911] specifies UNTIL date, time & new GMTOFF: + 0:52:04 - LMT 1911-12-31 23:00u 1:00 - WAT The decree specifies that Goa (Panaji) and Timor (Aisa/Dili) should keep the time scale of the adjacent colonies. Michael Deckers.

2 1