From 8587fdfc717f8ec9c925ba93b9cab7209820e83d Mon Sep 17 00:00:00 2001 From: Tim Parenti Date: Fri, 19 Jun 2026 11:41:03 -0400 Subject: Alberta's change became official on 2026-06-18 * NEWS: Mention this and update surrounding commentary. * northamerica (America/Edmonton): Now permanently on -06. Model this with abbreviation CST. Although the actual transition was legally on 2026-06-18, temporarily model the transition on 2026-11-01 at 02:00 to work around the same CLDR problems that we saw with BC. (America/Inuvik): Update commentary to reflect the latest implications for our Northwest Territories data. * zone.tab, zone1970.tab: Update comments. * zonenow.tab: New temporary entry for America/Edmonton until 2026-11-01. --- NEWS | 25 ++++++++++++++++-------- northamerica | 54 +++++++++++++++++++++++++++------------------------- zone.tab | 2 +- zone1970.tab | 2 +- zonenow.tab | 3 +++ 5 files changed, 50 insertions(+), 36 deletions(-) diff --git a/NEWS b/NEWS index bb912dc..042602c 100644 --- a/NEWS +++ b/NEWS @@ -3,8 +3,19 @@ News for the tz database Unreleased, experimental changes Briefly: + Alberta moved to permanent -06 on 2026-06-18. Another integer overflow bug has been fixed in zic. + Changes to future timestamps + + Alberta’s 2026-03-08 spring forward was its last foreseeable clock + change, as it moved to permanent -06 thereafter. (Thanks to Roozbeh + Pournader and others.) Model this with its traditional abbreviation + CST. Although the change to permanent -06 legally took place on + 2026-06-18, temporarily model the change to occur on 2026-11-01 at + 02:00 instead, for the same reason we introduced a similarly + temporary hack for British Columbia in 2026b. + Changes to code zic no longer overflows an integer when processing outlandish @@ -13,14 +24,12 @@ Unreleased, experimental changes Changes to commentary - The 2026-03-08 spring forward in Alberta and in Northwest - Territories was likely the last foreseeable clock change there, - as these areas are expected to move to permanent -06 thereafter. - (Thanks to Roozbeh Pournader and others.) This will affect UT - offsets starting 2026-11-01 02:00, when clocks would otherwise - fall back. Model this with its traditional abbreviation CST. - Unfortunately the change is not yet official, so it is currently - present only as comments that can be uncommented as needed. + Northwest Territories is expected to move to permanent -06 prior to + 2026-11-01 02:00, when clocks would otherwise fall back. (Thanks to + Tim Parenti and James Bellaire.) Model this with its traditional + abbreviation CST. Unfortunately the change is not yet official, so + it is currently present only as comments that can be uncommented as + needed. Changes to build procedure diff --git a/northamerica b/northamerica index 7297301..4ae6f45 100644 --- a/northamerica +++ b/northamerica @@ -1933,29 +1933,28 @@ Zone America/Swift_Current -7:11:20 - LMT 1905 Sep # https://calgaryherald.com/opinion/columnists/bell-alberta-daylight-time-year-round-premier-danielle-smith # # From Tim Parenti (2026-04-23): -# Bill 31, the Red Tape Reduction Statutes Amendment Act, 2026 +# Section 3 of Bill 31, the Red Tape Reduction Statutes Amendment Act, 2026 # https://docs.assembly.ab.ca/LADDAR_files/docs/bills/bill/legislature_31/session_2/20251023_bill-031.pdf # would repeal the Daylight Saving Time Act in the Revised Statues of Alberta # 2000 Chapter D-5: # https://kings-printer.alberta.ca/documents/Acts/D05.pdf # ...and substitutes a new chapter with language that closely parallels the -# original. The new title is the Official Time Act and would be numbered -# Chapter O-5.7. The bill would establish a standard time of UTC−6 without +# original. The new title is the Official Time Act and will be numbered +# Chapter O-5.7. The Act establishes a standard time of UTC−6 without # replacing the language previously used to effectuate DST. # -# From Tim Parenti (2026-05-14): -# Royal Assent...was announced this morning. The stated intent of Alberta's -# government has been to have this in place prior to when the clocks would -# otherwise fall back on 2026-11-01. For now, use that date pending the Order -# in Council. This also works around potential CLDR limitations in the -# meantime; see British Columbia, below. -# -# From Paul Eggert (2026-06-12): -# Need a legal citation for the official 2026 change to the law. The bill -# specifies UT offset only; abbreviate it as CST for consistency. It requires -# an Order in Council signed by the Lieutenant Governor before it becomes -# legally binding. As this has not yet happened, the changes are commented -# out for now in America/Edmonton. Similarly for America/Inuvik. +# From Tim Parenti (2026-06-19): +# After receiving Royal Assent on 2026-05-14, Order in Council 204/2026 was +# issued on 2026-06-18 proclaiming the relevant section of the bill in force on +# the same date. Order in Council 206/2026, issued the same day, uses the +# regulatory authority within the Act to prescribe the official term "Alberta +# Time"; we use the traditional abbreviation CST for consistency. +# https://kings-printer.alberta.ca/Documents/Orders/Orders_in_Council/2026/2026_204.pdf +# https://kings-printer.alberta.ca/Documents/Orders/Orders_in_Council/2026/2026_206.pdf +# +# Since wall clock times do not diverge from past practice until 2026-11-01, +# use that transition date for now to work around potential CLDR limitations in +# the meantime; see British Columbia, below. # Rule NAME FROM TO - IN ON AT SAVE LETTER/S Rule Edm 1918 1919 - Apr Sun>=8 2:00 1:00 D @@ -1974,11 +1973,11 @@ Rule Edm 1972 2006 - Oct lastSun 2:00 0 S # Zone NAME STDOFF RULES FORMAT [UNTIL] Zone America/Edmonton -7:33:52 - LMT 1906 Sep -7:00 Edm M%sT 1987 - -7:00 Canada M%sT -# Assuming the relevant part of Red Tape Reduction Statutes Amendment Act, 2026 -# takes effect on 2026-11-01 at 02:00, replace the above line with: -# -7:00 Canada M%sT 2026 Nov 1 2:00 -# -6:00 - CST + -7:00 Canada M%sT 2026 Jun 18 + # Temporary hack; see above. + -7:00 1:00 MDT 2026 Nov 1 2:00 + # End of temporary hack. + -6:00 - CST # British Columbia @@ -2420,12 +2419,15 @@ Zone America/Fort_Nelson -8:10:47 - LMT 1884 # end seasonal time changes until Alberta does." # https://www.cbc.ca/news/canada/north/nwt-ends-daylight-saving-9.7170964 # -# From Tim Parenti (2026-06-11), per James Bellaire (2026-06-02): -# Much of NWT is currently represented by America/Edmonton, which alias +# From Tim Parenti (2026-06-19), per James Bellaire (2026-06-02): +# Much of NWT has, to date, been represented by America/Edmonton, which alias # America/Yellowknife links to. While Bill 13 (assented to 2021-03-31) would # enable NWT's proposed change mirroring Alberta's, at time of writing it has # not yet been formally enacted; if it doesn't move forward as expected, -# America/Yellowknife would need to become its own zone. +# America/Yellowknife would need to become its own zone as Alberta has stopped +# changing its clocks. +# If it does go ahead, draft changes to America/Inuvik, which represents the +# remainder of NWT, are commented below. # Rule NAME FROM TO - IN ON AT SAVE LETTER/S Rule NT_YK 1918 only - Apr 14 2:00 1:00 D @@ -2469,8 +2471,8 @@ Zone America/Inuvik 0 - -00 1953 # Inuvik founded -8:00 NT_YK P%sT 1979 Apr lastSun 2:00 -7:00 NT_YK M%sT 1980 -7:00 Canada M%sT -# Assuming Alberta stops changing clocks in fall 2026 and Northwest Territories -# follow Alberta, replace the above line with: +# Assuming Northwest Territories follow Alberta in abolishing seasonal time +# changes, replace the above line with something like: # -7:00 Canada M%sT 2026 Nov 1 2:00 # -6:00 - CST Zone America/Whitehorse -9:00:12 - LMT 1900 Aug 20 diff --git a/zone.tab b/zone.tab index 2ae8a8c..69d50bd 100644 --- a/zone.tab +++ b/zone.tab @@ -121,7 +121,7 @@ CA +744144-0944945 America/Resolute Central - NU (Resolute) CA +624900-0920459 America/Rankin_Inlet Central - NU (central) CA +5024-10439 America/Regina CST - SK (most areas) CA +5017-10750 America/Swift_Current CST - SK (midwest) -CA +5333-11328 America/Edmonton Mountain - AB, BC(E), NT(E), SK(W) +CA +5333-11328 America/Edmonton CST - AB, BC(E), NT(E), SK(W) CA +690650-1050310 America/Cambridge_Bay Mountain - NU (west) CA +682059-1334300 America/Inuvik Mountain - NT (west) CA +4916-12307 America/Vancouver MST - BC (most areas) diff --git a/zone1970.tab b/zone1970.tab index a9b47bc..635eabc 100644 --- a/zone1970.tab +++ b/zone1970.tab @@ -112,7 +112,7 @@ CA +744144-0944945 America/Resolute Central - NU (Resolute) CA +624900-0920459 America/Rankin_Inlet Central - NU (central) CA +5024-10439 America/Regina CST - SK (most areas) CA +5017-10750 America/Swift_Current CST - SK (midwest) -CA +5333-11328 America/Edmonton Mountain - AB, BC(E), NT(E), SK(W) +CA +5333-11328 America/Edmonton CST - AB, BC(E), NT(E), SK(W) CA +690650-1050310 America/Cambridge_Bay Mountain - NU (west) CA +682059-1334300 America/Inuvik Mountain - NT (west) CA +4916-12307 America/Vancouver MST - BC (most areas) diff --git a/zonenow.tab b/zonenow.tab index c499cc8..e6babe8 100644 --- a/zonenow.tab +++ b/zonenow.tab @@ -67,6 +67,9 @@ XX +332654-1120424 America/Phoenix Mountain Standard (MST) - Arizona; western Me # -07/-06 - MST/MDT (North America DST) XX +394421-1045903 America/Denver Mountain (MST/MDT) - US & Canada; Mexico near US border # +# -07/-06 - MST/MDT (North America DST) until 2026-11-01 02:00; then CST +XX +5333-11328 America/Edmonton Central Standard (CST) - Alberta and some neighbors +# # -06 XX -0054-08936 Pacific/Galapagos Galápagos # -- 2.50.1 (Apple Git-155)