- tz - lists.iana.org

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

July 27, 2017

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

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

July 20, 2017

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

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

July 18, 2017

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

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

July 16, 2017

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

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

July 14, 2017

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

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

July 14, 2017

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

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

July 11, 2017

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

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IERS Bulletin C54
by Michael Deckers July 11, 2017

July 11, 2017

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

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

July 10, 2017

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

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

July 8, 2017

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

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