1 files changed, 238 insertions, 56 deletions

diff --git a/contrib/tzdata/backward b/contrib/tzdata/backward
index 7685c7429c50..65c711b37bf4 100644
--- a/contrib/tzdata/backward
+++ b/contrib/tzdata/backward
@@ -4,54 +4,33 @@
 # 2009-05-17 by Arthur David Olson.
 
 # This file provides links from old or merged timezone names to current ones.
-# Many names changed in late 1993.  Several of these names are
+# Many names changed in 1993 and in 1995, and many merged names moved here
+# in the period from 2013 through 2022.  Several of these names are
 # also present in the file 'backzone', which has data important only
 # for pre-1970 timestamps and so is out of scope for tzdb proper.
 
-# Link	TARGET			LINK-NAME
-Link	Africa/Nairobi		Africa/Asmera
-Link	Africa/Abidjan		Africa/Timbuktu
-Link	America/Argentina/Catamarca	America/Argentina/ComodRivadavia
-Link	America/Adak		America/Atka
-Link	America/Argentina/Buenos_Aires	America/Buenos_Aires
-Link	America/Argentina/Catamarca	America/Catamarca
-Link	America/Panama		America/Coral_Harbour
-Link	America/Argentina/Cordoba	America/Cordoba
-Link	America/Tijuana		America/Ensenada
-Link	America/Indiana/Indianapolis	America/Fort_Wayne
-Link	America/Nuuk		America/Godthab
-Link	America/Indiana/Indianapolis	America/Indianapolis
-Link	America/Argentina/Jujuy	America/Jujuy
-Link	America/Indiana/Knox	America/Knox_IN
-Link	America/Kentucky/Louisville	America/Louisville
-Link	America/Argentina/Mendoza	America/Mendoza
-Link	America/Toronto		America/Montreal
-Link	America/Rio_Branco	America/Porto_Acre
-Link	America/Argentina/Cordoba	America/Rosario
-Link	America/Tijuana		America/Santa_Isabel
-Link	America/Denver		America/Shiprock
-Link	America/Puerto_Rico	America/Virgin
-Link	Pacific/Auckland	Antarctica/South_Pole
-Link	Asia/Ashgabat		Asia/Ashkhabad
-Link	Asia/Kolkata		Asia/Calcutta
-Link	Asia/Shanghai		Asia/Chongqing
-Link	Asia/Shanghai		Asia/Chungking
-Link	Asia/Dhaka		Asia/Dacca
-Link	Asia/Shanghai		Asia/Harbin
-Link	Asia/Urumqi		Asia/Kashgar
-Link	Asia/Kathmandu		Asia/Katmandu
-Link	Asia/Macau		Asia/Macao
-Link	Asia/Yangon		Asia/Rangoon
-Link	Asia/Ho_Chi_Minh	Asia/Saigon
-Link	Asia/Jerusalem		Asia/Tel_Aviv
-Link	Asia/Thimphu		Asia/Thimbu
-Link	Asia/Makassar		Asia/Ujung_Pandang
-Link	Asia/Ulaanbaatar	Asia/Ulan_Bator
-Link	Atlantic/Faroe		Atlantic/Faeroe
-Link	Europe/Oslo		Atlantic/Jan_Mayen
-Link	Australia/Sydney	Australia/ACT
-Link	Australia/Sydney	Australia/Canberra
-Link	Australia/Hobart	Australia/Currie
+# Although this file is optional and tzdb will work if you omit it by
+# building with 'make BACKWARD=', in practice downstream users
+# typically use this file for backward compatibility.
+
+# This file is divided into sections, one for each major reason for a
+# backward compatibility link.  Each section is sorted by link name.
+
+# A "#= TARGET1" comment labels each link inserted only because some
+# .zi parsers (including tzcode through 2022e) mishandle links to links.
+# The comment says what the target would be if these parsers were fixed
+# so that data could contain links to links.  For example, the line
+# "Link Australia/Sydney Australia/ACT #= Australia/Canberra" would be
+# "Link Australia/Canberra Australia/ACT" were it not that data lines
+# refrain from linking to links like Australia/Canberra, which means
+# the Australia/ACT line links instead to Australia/Sydney,
+# Australia/Canberra's target.
+
+
+# Pre-1993 naming conventions
+
+# Link	TARGET			LINK-NAME	#= TARGET1
+Link	Australia/Sydney	Australia/ACT	#= Australia/Canberra
 Link	Australia/Lord_Howe	Australia/LHI
 Link	Australia/Sydney	Australia/NSW
 Link	Australia/Darwin	Australia/North
@@ -61,7 +40,7 @@ Link	Australia/Hobart	Australia/Tasmania
 Link	Australia/Melbourne	Australia/Victoria
 Link	Australia/Perth		Australia/West
 Link	Australia/Broken_Hill	Australia/Yancowinna
-Link	America/Rio_Branco	Brazil/Acre
+Link	America/Rio_Branco	Brazil/Acre	#= America/Porto_Acre
 Link	America/Noronha		Brazil/DeNoronha
 Link	America/Sao_Paulo	Brazil/East
 Link	America/Manaus		Brazil/West
@@ -81,17 +60,36 @@ Link	Pacific/Easter		Chile/EasterIsland
 Link	America/Havana		Cuba
 Link	Africa/Cairo		Egypt
 Link	Europe/Dublin		Eire
+# Vanguard section, for most .zi parsers.
+#Link	GMT			Etc/GMT
+#Link	GMT			Etc/GMT+0
+#Link	GMT			Etc/GMT-0
+#Link	GMT			Etc/GMT0
+#Link	GMT			Etc/Greenwich
+# Rearguard section, for TZUpdater 2.3.2 and earlier.
+Link	Etc/GMT			Etc/GMT+0
+Link	Etc/GMT			Etc/GMT-0
+Link	Etc/GMT			Etc/GMT0
+Link	Etc/GMT			Etc/Greenwich
+# End of rearguard section.
 Link	Etc/UTC			Etc/UCT
-Link	Europe/London		Europe/Belfast
-Link	Europe/Chisinau		Europe/Tiraspol
+Link	Etc/UTC			Etc/Universal
+Link	Etc/UTC			Etc/Zulu
 Link	Europe/London		GB
 Link	Europe/London		GB-Eire
+# Vanguard section, for most .zi parsers.
+#Link	GMT			GMT+0
+#Link	GMT			GMT-0
+#Link	GMT			GMT0
+#Link	GMT			Greenwich
+# Rearguard section, for TZUpdater 2.3.2 and earlier.
 Link	Etc/GMT			GMT+0
 Link	Etc/GMT			GMT-0
 Link	Etc/GMT			GMT0
 Link	Etc/GMT			Greenwich
+# End of rearguard section.
 Link	Asia/Hong_Kong		Hongkong
-Link	Atlantic/Reykjavik	Iceland
+Link	Africa/Abidjan		Iceland	#= Atlantic/Reykjavik
 Link	Asia/Tehran		Iran
 Link	Asia/Jerusalem		Israel
 Link	America/Jamaica		Jamaica
@@ -103,14 +101,8 @@ Link	America/Mazatlan	Mexico/BajaSur
 Link	America/Mexico_City	Mexico/General
 Link	Pacific/Auckland	NZ
 Link	Pacific/Chatham		NZ-CHAT
-Link	America/Denver		Navajo
+Link	America/Denver		Navajo	#= America/Shiprock
 Link	Asia/Shanghai		PRC
-Link	Pacific/Kanton		Pacific/Enderbury
-Link	Pacific/Honolulu	Pacific/Johnston
-Link	Pacific/Pohnpei		Pacific/Ponape
-Link	Pacific/Pago_Pago	Pacific/Samoa
-Link	Pacific/Chuuk		Pacific/Truk
-Link	Pacific/Chuuk		Pacific/Yap
 Link	Europe/Warsaw		Poland
 Link	Europe/Lisbon		Portugal
 Link	Asia/Taipei		ROC
@@ -134,3 +126,193 @@ Link	Etc/UTC			UTC
 Link	Etc/UTC			Universal
 Link	Europe/Moscow		W-SU
 Link	Etc/UTC			Zulu
+
+
+# Two-part names that were renamed mostly to three-part names in 1995
+
+# Link	TARGET				LINK-NAME	#= TARGET1
+Link	America/Argentina/Buenos_Aires	America/Buenos_Aires
+Link	America/Argentina/Catamarca	America/Catamarca
+Link	America/Argentina/Cordoba	America/Cordoba
+Link	America/Indiana/Indianapolis	America/Indianapolis
+Link	America/Argentina/Jujuy		America/Jujuy
+Link	America/Indiana/Knox		America/Knox_IN
+Link	America/Kentucky/Louisville	America/Louisville
+Link	America/Argentina/Mendoza	America/Mendoza
+Link	America/Puerto_Rico		America/Virgin	#= America/St_Thomas
+Link	Pacific/Pago_Pago		Pacific/Samoa
+
+
+# Pre-2013 practice, which typically had a Zone per zone.tab line
+
+# Link	TARGET			LINK-NAME
+Link	Africa/Abidjan		Africa/Accra
+Link	Africa/Nairobi		Africa/Addis_Ababa
+Link	Africa/Nairobi		Africa/Asmara
+Link	Africa/Abidjan		Africa/Bamako
+Link	Africa/Lagos		Africa/Bangui
+Link	Africa/Abidjan		Africa/Banjul
+Link	Africa/Maputo		Africa/Blantyre
+Link	Africa/Lagos		Africa/Brazzaville
+Link	Africa/Maputo		Africa/Bujumbura
+Link	Africa/Abidjan		Africa/Conakry
+Link	Africa/Abidjan		Africa/Dakar
+Link	Africa/Nairobi		Africa/Dar_es_Salaam
+Link	Africa/Nairobi		Africa/Djibouti
+Link	Africa/Lagos		Africa/Douala
+Link	Africa/Abidjan		Africa/Freetown
+Link	Africa/Maputo		Africa/Gaborone
+Link	Africa/Maputo		Africa/Harare
+Link	Africa/Nairobi		Africa/Kampala
+Link	Africa/Maputo		Africa/Kigali
+Link	Africa/Lagos		Africa/Kinshasa
+Link	Africa/Lagos		Africa/Libreville
+Link	Africa/Abidjan		Africa/Lome
+Link	Africa/Lagos		Africa/Luanda
+Link	Africa/Maputo		Africa/Lubumbashi
+Link	Africa/Maputo		Africa/Lusaka
+Link	Africa/Lagos		Africa/Malabo
+Link	Africa/Johannesburg	Africa/Maseru
+Link	Africa/Johannesburg	Africa/Mbabane
+Link	Africa/Nairobi		Africa/Mogadishu
+Link	Africa/Lagos		Africa/Niamey
+Link	Africa/Abidjan		Africa/Nouakchott
+Link	Africa/Abidjan		Africa/Ouagadougou
+Link	Africa/Lagos		Africa/Porto-Novo
+Link	America/Puerto_Rico	America/Anguilla
+Link	America/Puerto_Rico	America/Antigua
+Link	America/Puerto_Rico	America/Aruba
+Link	America/Panama		America/Atikokan
+Link	America/Puerto_Rico	America/Blanc-Sablon
+Link	America/Panama		America/Cayman
+Link	America/Phoenix		America/Creston
+Link	America/Puerto_Rico	America/Curacao
+Link	America/Puerto_Rico	America/Dominica
+Link	America/Puerto_Rico	America/Grenada
+Link	America/Puerto_Rico	America/Guadeloupe
+Link	America/Puerto_Rico	America/Kralendijk
+Link	America/Puerto_Rico	America/Lower_Princes
+Link	America/Puerto_Rico	America/Marigot
+Link	America/Puerto_Rico	America/Montserrat
+Link	America/Toronto		America/Nassau
+Link	America/Puerto_Rico	America/Port_of_Spain
+Link	America/Puerto_Rico	America/St_Barthelemy
+Link	America/Puerto_Rico	America/St_Kitts
+Link	America/Puerto_Rico	America/St_Lucia
+Link	America/Puerto_Rico	America/St_Thomas
+Link	America/Puerto_Rico	America/St_Vincent
+Link	America/Puerto_Rico	America/Tortola
+Link	Pacific/Port_Moresby	Antarctica/DumontDUrville
+Link	Pacific/Auckland	Antarctica/McMurdo
+Link	Asia/Riyadh		Antarctica/Syowa
+Link	Europe/Berlin		Arctic/Longyearbyen
+Link	Asia/Riyadh		Asia/Aden
+Link	Asia/Qatar		Asia/Bahrain
+Link	Asia/Kuching		Asia/Brunei
+Link	Asia/Singapore		Asia/Kuala_Lumpur
+Link	Asia/Riyadh		Asia/Kuwait
+Link	Asia/Dubai		Asia/Muscat
+Link	Asia/Bangkok		Asia/Phnom_Penh
+Link	Asia/Bangkok		Asia/Vientiane
+Link	Africa/Abidjan		Atlantic/Reykjavik
+Link	Africa/Abidjan		Atlantic/St_Helena
+Link	Europe/Brussels		Europe/Amsterdam
+Link	Europe/Prague		Europe/Bratislava
+Link	Europe/Zurich		Europe/Busingen
+Link	Europe/Berlin		Europe/Copenhagen
+Link	Europe/London		Europe/Guernsey
+Link	Europe/London		Europe/Isle_of_Man
+Link	Europe/London		Europe/Jersey
+Link	Europe/Belgrade		Europe/Ljubljana
+Link	Europe/Brussels		Europe/Luxembourg
+Link	Europe/Helsinki		Europe/Mariehamn
+Link	Europe/Paris		Europe/Monaco
+Link	Europe/Berlin		Europe/Oslo
+Link	Europe/Belgrade		Europe/Podgorica
+Link	Europe/Rome		Europe/San_Marino
+Link	Europe/Belgrade		Europe/Sarajevo
+Link	Europe/Belgrade		Europe/Skopje
+Link	Europe/Berlin		Europe/Stockholm
+Link	Europe/Zurich		Europe/Vaduz
+Link	Europe/Rome		Europe/Vatican
+Link	Europe/Belgrade		Europe/Zagreb
+Link	Africa/Nairobi		Indian/Antananarivo
+Link	Asia/Bangkok		Indian/Christmas
+Link	Asia/Yangon		Indian/Cocos
+Link	Africa/Nairobi		Indian/Comoro
+Link	Indian/Maldives		Indian/Kerguelen
+Link	Asia/Dubai		Indian/Mahe
+Link	Africa/Nairobi		Indian/Mayotte
+Link	Asia/Dubai		Indian/Reunion
+Link	Pacific/Port_Moresby	Pacific/Chuuk
+Link	Pacific/Tarawa		Pacific/Funafuti
+Link	Pacific/Tarawa		Pacific/Majuro
+Link	Pacific/Pago_Pago	Pacific/Midway
+Link	Pacific/Guadalcanal	Pacific/Pohnpei
+Link	Pacific/Guam		Pacific/Saipan
+Link	Pacific/Tarawa		Pacific/Wake
+Link	Pacific/Tarawa		Pacific/Wallis
+
+
+# Non-zone.tab locations with timestamps since 1970 that duplicate
+# those of an existing location
+
+# Link	TARGET			LINK-NAME
+Link	Africa/Abidjan		Africa/Timbuktu
+Link	America/Argentina/Catamarca	America/Argentina/ComodRivadavia
+Link	America/Adak		America/Atka
+Link	America/Panama		America/Coral_Harbour
+Link	America/Tijuana		America/Ensenada
+Link	America/Indiana/Indianapolis	America/Fort_Wayne
+Link	America/Toronto		America/Montreal
+Link	America/Toronto		America/Nipigon
+Link	America/Iqaluit		America/Pangnirtung
+Link	America/Rio_Branco	America/Porto_Acre
+Link	America/Winnipeg	America/Rainy_River
+Link	America/Argentina/Cordoba	America/Rosario
+Link	America/Tijuana		America/Santa_Isabel
+Link	America/Denver		America/Shiprock
+Link	America/Toronto		America/Thunder_Bay
+Link	America/Edmonton	America/Yellowknife
+Link	Pacific/Auckland	Antarctica/South_Pole
+Link	Asia/Shanghai		Asia/Chongqing
+Link	Asia/Shanghai		Asia/Harbin
+Link	Asia/Urumqi		Asia/Kashgar
+Link	Asia/Jerusalem		Asia/Tel_Aviv
+Link	Europe/Berlin		Atlantic/Jan_Mayen
+Link	Australia/Sydney	Australia/Canberra
+Link	Australia/Hobart	Australia/Currie
+Link	Europe/London		Europe/Belfast
+Link	Europe/Chisinau		Europe/Tiraspol
+Link	Europe/Kyiv		Europe/Uzhgorod
+Link	Europe/Kyiv		Europe/Zaporozhye
+Link	Pacific/Kanton		Pacific/Enderbury
+Link	Pacific/Honolulu	Pacific/Johnston
+Link	Pacific/Port_Moresby	Pacific/Yap
+
+
+# Alternate names for the same location
+
+# Link	TARGET			LINK-NAME	#= TARGET1
+Link	Africa/Nairobi		Africa/Asmera	#= Africa/Asmara
+Link	America/Nuuk		America/Godthab
+Link	Asia/Ashgabat		Asia/Ashkhabad
+Link	Asia/Kolkata		Asia/Calcutta
+Link	Asia/Shanghai		Asia/Chungking	#= Asia/Chongqing
+Link	Asia/Dhaka		Asia/Dacca
+# Istanbul is in both continents.
+Link	Europe/Istanbul		Asia/Istanbul
+Link	Asia/Kathmandu		Asia/Katmandu
+Link	Asia/Macau		Asia/Macao
+Link	Asia/Yangon		Asia/Rangoon
+Link	Asia/Ho_Chi_Minh	Asia/Saigon
+Link	Asia/Thimphu		Asia/Thimbu
+Link	Asia/Makassar		Asia/Ujung_Pandang
+Link	Asia/Ulaanbaatar	Asia/Ulan_Bator
+Link	Atlantic/Faroe		Atlantic/Faeroe
+Link	Europe/Kyiv		Europe/Kiev
+# Classically, Cyprus is in Asia; e.g. see Herodotus, Histories, I.72.
+# However, for various reasons many users expect to find it under Europe.
+Link	Asia/Nicosia		Europe/Nicosia
+Link	Pacific/Guadalcanal	Pacific/Ponape	#= Pacific/Pohnpei
+Link	Pacific/Port_Moresby	Pacific/Truk	#= Pacific/Chuuk