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 fall.
The current database returns times for summer of 2018 as GMT -5, which is incorrect.
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 Briefly: 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 ... # https://www.gov.uk/government/news/turks-and-caicos-post-cabinet-meeting-sta... # # 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. # http://magneticmediatv.com/2017/08/time-change-back-by-march-2018-for-tci/ # # 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