[tz] [PROPOSED] America/Yellowknife now links to America/Edmonton

[Paul Eggert]

(Thanks to Almaz Mingaleev.)
* NEWS: Mention this.
* backzone (America/Yellowknife): Move Zone here ...
* northamerica: ... from here.
* zone.tab, zone1970.tab: Remove America/Yellowknife.
---
 NEWS         | 8 ++++++++
 backzone     | 5 +++++
 northamerica | 7 -------
 zone.tab     | 3 +--
 zone1970.tab | 3 +--
 5 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/NEWS b/NEWS
index ac0b611a..98cc14f7 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,7 @@ Unreleased, experimental changes
 
   Briefly:
     Much of Greenland still uses DST from 2024 on.
+    America/Yellowknife now links to America/Edmonton.
     The code now defaults to C99 or later.
     Fix use of C23 attributes.
 
@@ -17,6 +18,13 @@ Unreleased, experimental changes
     This change from 2022g doesn't affect timestamps until 2024-03-30,
     and doesn't affect tm_isdst until 2023-03-25.
 
+  Changes to past timestamps
+
+    America/Yellowknife has changed from a Zone to a backward
+    compatibility Link, as it no longer differs from America/Edmonton
+    since 1970.  (Thanks to Almaz Mingaleev.)  This affects some
+    pre-1948 timestamps.  The old data are now in 'backzone'.
+
   Changes to code
 
     The code by default is now designed for C99 or later.  To build in
diff --git a/backzone b/backzone
index 7803c57d..1bd23ac6 100644
--- a/backzone
+++ b/backzone
@@ -928,6 +928,11 @@ Zone America/Thunder_Bay -5:57:00 -	LMT	1895
 Zone America/Tortola	-4:18:28 -	LMT	1911 Jul # Road Town
 			-4:00	-	AST
 
+# Yellowknife, Northwest Territories
+Zone America/Yellowknife 0	-	-00	1935 # Yellowknife founded?
+			-7:00	NT_YK	M%sT	1980
+			-7:00	Canada	M%sT
+
 # Dumont d'Urville, Île des Pétrels, -6640+14001, since 1956-11
 # <https://en.wikipedia.org/wiki/Dumont_d'Urville_Station> (2005-12-05)
 #
diff --git a/northamerica b/northamerica
index e33701bf..24b68e72 100644
--- a/northamerica
+++ b/northamerica
@@ -2125,10 +2125,6 @@ Zone America/Fort_Nelson	-8:10:47 -	LMT	1884
 # Nunavut ... moved ... to incorporate the whole territory into one time zone.
 # Nunavut moves to single time zone Oct. 31
 # http://www.nunatsiaq.com/nunavut/nvt90903_13.html
-#
-# From Antoine Leca (1999-09-06):
-# We then need to create a new timezone for the Kitikmeot region of Nunavut
-# to differentiate it from the Yellowknife region.
 
 # From Paul Eggert (1999-09-20):
 # Basic Facts: The New Territory
@@ -2322,9 +2318,6 @@ Zone America/Cambridge_Bay 0	-	-00	1920 # trading post est.?
 			-5:00	-	EST	2000 Nov  5  0:00
 			-6:00	-	CST	2001 Apr  1  3:00
 			-7:00	Canada	M%sT
-Zone America/Yellowknife 0	-	-00	1935 # Yellowknife founded?
-			-7:00	NT_YK	M%sT	1980
-			-7:00	Canada	M%sT
 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
diff --git a/zone.tab b/zone.tab
index 6e5adb9f..5d5c79ff 100644
--- a/zone.tab
+++ b/zone.tab
@@ -121,9 +121,8 @@ 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); SK (W)
+CA	+5333-11328	America/Edmonton	Mountain - AB; BC (E); NT (E); SK (W)
 CA	+690650-1050310	America/Cambridge_Bay	Mountain - NU (west)
-CA	+6227-11421	America/Yellowknife	Mountain - NT (central)
 CA	+682059-1334300	America/Inuvik	Mountain - NT (west)
 CA	+4906-11631	America/Creston	MST - BC (Creston)
 CA	+5546-12014	America/Dawson_Creek	MST - BC (Dawson Cr, Ft St John)
diff --git a/zone1970.tab b/zone1970.tab
index a9b36d36..819316be 100644
--- a/zone1970.tab
+++ b/zone1970.tab
@@ -108,9 +108,8 @@ 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); SK (W)
+CA	+5333-11328	America/Edmonton	Mountain - AB; BC (E); NT (E); SK (W)
 CA	+690650-1050310	America/Cambridge_Bay	Mountain - NU (west)
-CA	+6227-11421	America/Yellowknife	Mountain - NT (central)
 CA	+682059-1334300	America/Inuvik	Mountain - NT (west)
 CA	+5546-12014	America/Dawson_Creek	MST - BC (Dawson Cr, Ft St John)
 CA	+5848-12242	America/Fort_Nelson	MST - BC (Ft Nelson)
-- 
2.37.2