[tz] Incorrect Time Zone Data for American/Grand_Turk
Brian.Inglis at SystematicSw.ab.ca
Tue Jul 24 15:50:24 UTC 2018
On 2018-07-23 10:48, Robert MacGrogan wrote:
> It looks to me like the time zone data for America/Grand_Turk is incorrect
> in 2018e version of the database. Turks and Caicos switched to supporting
> daylight savings time in March of 2018. So in summer the correct time for
> America/Ground_Turk should be GMT -4 and then back to GMT -5 again in the
> The current database returns times for summer of 2018 as GMT -5, which is
Your installed time zone data may be incorrect but 2018e is correct:
$ TZ=America/Grand_Turk date +%c%z%Z
2018 Jul 24 Tue 10:31:25-0400EDT
$ apt list tzdata
tzdata 2018e-1 x86_64 [installed, automatic]
and has not changed since the TCI announcement in 2017, updated in 2017c,
generated on Oct 20, released on Oct 23 (boy, was last year controlled?):
$ head -20 tz/releases/tzdata2017c/NEWS
News for the tz database
Release 2017c - 2017-10-20 14:49:34 -0700
Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
Fiji ends DST 2018-01-14, not 2018-01-21.
Namibia switches from +01/+02 to +02 on 2018-04-01.
Sudan switches from +03 to +02 on 2017-11-01.
Tonga likely switches from +13/+14 to +13 on 2017-11-05.
Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
when northamerica was changed:
# From the Turks & Caicos Cabinet (2017-07-20), heads-up from Steffen Thorsen:
# ... agreed to the reintroduction in TCI of Daylight Saving Time (DST)
# during the summer months and Standard Time, also known as Local
# Time, during the winter months with effect from April 2018 ...
# From Paul Eggert (2017-08-26):
# The date of effect of the spring 2018 change appears to be March 11,
# which makes more sense. See: Hamilton D. Time change back
# by March 2018 for TCI. Magnetic Media. 2017-08-25.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Grand_Turk -4:44:32 - LMT 1890
-5:07:10 - KMT 1912 Feb # Kingston Mean Time
-5:00 - EST 1979
-5:00 US E%sT 2015 Nov Sun>=1 2:00
-4:00 - AST 2018 Mar 11 3:00
-5:00 US E%sT
which shows EST between 1912-1979, EST/EDT until 2015, rezone and stay on AST
until 2018, then back to EDT/EST on US rules.
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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