diff --git a/Directory.Build.props b/Directory.Build.props
index 5b98c96..6e20627 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -1,7 +1,7 @@
 <Project>
 
   <PropertyGroup>
-    <LangVersion>10</LangVersion>
+    <LangVersion>latest</LangVersion>
     <ImplicitUsings>true</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
@@ -12,7 +12,6 @@
 
   <ItemGroup>
     <PackageReference Include="Roslynator.Analyzers" Version="4.12.10" PrivateAssets="All" />
-    <PackageReference Include="Nullable" Version="1.3.1" PrivateAssets="All" />
   </ItemGroup>
 
 </Project>
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index d490252..48528f9 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -17,4 +17,8 @@
     <AnalysisLevel>latest-Recommended</AnalysisLevel>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Polyfill" Version="8.9.0" PrivateAssets="All" />
+  </ItemGroup>
+
 </Project>
diff --git a/src/TimeZoneConverter.DataBuilder/Program.cs b/src/TimeZoneConverter.DataBuilder/Program.cs
index e19983a..b56f4c1 100644
--- a/src/TimeZoneConverter.DataBuilder/Program.cs
+++ b/src/TimeZoneConverter.DataBuilder/Program.cs
@@ -50,10 +50,6 @@ public static void Main(string[] args)
             // Remove the alias for "Etc/Unknown Factory" as it's not a valid zone.
             aliases.Remove("Etc/Unknown,Factory");
 
-            // Add missing Rails mappings where they make sense
-            railsMapping.Remove("Arizona,America/Phoenix");
-            railsMapping.Add("Arizona,America/Phoenix America/Whitehorse");
-
             // Add mappings for ISO country codes that aren't used in CLDR
             mapping.Add("Romance Standard Time,EA,Africa/Ceuta");
             mapping.Add("GMT Standard Time,IC,Atlantic/Canary");
diff --git a/src/TimeZoneConverter/Data/RailsMapping.csv.gz b/src/TimeZoneConverter/Data/RailsMapping.csv.gz
index 8e6d013..4829cf7 100644
Binary files a/src/TimeZoneConverter/Data/RailsMapping.csv.gz and b/src/TimeZoneConverter/Data/RailsMapping.csv.gz differ
diff --git a/src/TimeZoneConverter/TZConvert.cs b/src/TimeZoneConverter/TZConvert.cs
index b28fa9f..8391e51 100644
--- a/src/TimeZoneConverter/TZConvert.cs
+++ b/src/TimeZoneConverter/TZConvert.cs
@@ -16,7 +16,7 @@ public static class TZConvert
     private static readonly Dictionary<string, IList<string>> InverseRailsMap = new(StringComparer.OrdinalIgnoreCase);
     private static readonly Dictionary<string, string> Links = new(StringComparer.OrdinalIgnoreCase);
     private static readonly Dictionary<string, TimeZoneInfo> SystemTimeZones;
-    
+
     private static readonly IDictionary<string, IList<string>> IanaTerritoryZones =
         new Dictionary<string, IList<string>>(StringComparer.OrdinalIgnoreCase);
 
@@ -78,7 +78,7 @@ public static IReadOnlyDictionary<string, IReadOnlyCollection<string>> GetIanaTi
             return new ReadOnlyDictionary<string, IReadOnlyCollection<string>>(
                 IanaTerritoryZones.ToDictionary(
                     x => x.Key,
-                    x => (IReadOnlyCollection<string>) x.Value
+                    x => (IReadOnlyCollection<string>)x.Value
                         .OrderBy(zone => zone)
                         .ToList().AsReadOnly()));
         }
@@ -87,7 +87,7 @@ public static IReadOnlyDictionary<string, IReadOnlyCollection<string>> GetIanaTi
         return new ReadOnlyDictionary<string, IReadOnlyCollection<string>>(
             IanaTerritoryZones.ToDictionary(
                 x => x.Key,
-                x => (IReadOnlyCollection<string>) x.Value
+                x => (IReadOnlyCollection<string>)x.Value
                     .Select(zone => TryIanaToWindows(zone, out var winId)
                         ? WindowsToIana(winId, x.Key)
                         : zone)
@@ -184,7 +184,7 @@ public static string WindowsToIana(string windowsTimeZoneId, string territoryCod
         throw new InvalidTimeZoneException(
             $"\"{windowsTimeZoneId}\" was not recognized as a valid Windows time zone ID.");
     }
-    
+
     /// <summary>
     /// Attempts to convert a Windows time zone ID to an equivalent IANA time zone name.
     /// Uses the "golden zone" - the one that is the most prevalent.
@@ -395,6 +395,23 @@ public static IList<string> IanaToRails(string ianaTimeZoneName)
     /// <returns><c>true</c> if successful, <c>false</c> otherwise.</returns>
     public static bool TryIanaToRails(string ianaTimeZoneName, out IList<string> railsTimeZoneNames)
     {
+
+        // in the case of an Etc/GMT+/-n zone, use the Rails fixed-offset zone.  For example, `Etc/GMT-6` -> `+06:00` or `Etc/GMT+3` -> `-03:00`
+        if (ianaTimeZoneName.StartsWith("Etc/GMT", StringComparison.OrdinalIgnoreCase))
+        {
+            var offsetPart = ianaTimeZoneName[7..];
+            if (offsetPart.Length > 2)
+            {
+                var sign = offsetPart[0];
+                if ((sign == '+' || sign == '-') && int.TryParse(offsetPart[1..], out var hours) && hours is >= 0 and <= 14)
+                {
+                    var offsetString = $"{(sign == '+' ? '-' : '+')}{hours:00}:00"; // note the inverted sign
+                    railsTimeZoneNames = [offsetString];
+                    return true;
+                }
+            }
+        }
+
         // try directly first
         if (InverseRailsMap.TryGetValue(ianaTimeZoneName, out railsTimeZoneNames!))
         {
@@ -409,6 +426,14 @@ public static bool TryIanaToRails(string ianaTimeZoneName, out IList<string> rai
             return true;
         }
 
+        // If it's a valid IANA zone, then just return it since Rails will accept it as-is.
+        if (KnownIanaTimeZoneNames.Contains(ianaTimeZoneName))
+        {
+            railsTimeZoneNames = [ianaTimeZoneName];
+            return true;
+        }
+
+        // not found
         railsTimeZoneNames = Array.Empty<string>();
         return false;
     }
@@ -531,6 +556,13 @@ public static bool TryWindowsToRails(string windowsTimeZoneId, out IList<string>
     public static bool TryWindowsToRails(string windowsTimeZoneId, string territoryCode,
         out IList<string> railsTimeZoneNames)
     {
+        // edge case "Dateline Standard Time" -> "International Date Line West"
+        if (string.Equals(windowsTimeZoneId, "Dateline Standard Time", StringComparison.OrdinalIgnoreCase))
+        {
+            railsTimeZoneNames = ["International Date Line West"];
+            return true;
+        }
+
         if (TryWindowsToIana(windowsTimeZoneId, territoryCode, out var ianaTimeZoneName) &&
             TryIanaToRails(ianaTimeZoneName, out railsTimeZoneNames))
         {
diff --git a/src/TimeZoneConverter/TimeZoneConverter.csproj b/src/TimeZoneConverter/TimeZoneConverter.csproj
index 40cebd9..a13369f 100644
--- a/src/TimeZoneConverter/TimeZoneConverter.csproj
+++ b/src/TimeZoneConverter/TimeZoneConverter.csproj
@@ -19,6 +19,7 @@
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net462'">
     <PackageReference Include="System.Runtime.InteropServices.RuntimeInformation" Version="4.3.0" />
+    <PackageReference Include="System.ValueTuple" Version="4.6.1" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/test/TimeZoneConverter.Tests/DataVerificationTests.Iana_To_Rails.verified.txt b/test/TimeZoneConverter.Tests/DataVerificationTests.Iana_To_Rails.verified.txt
index 6b9b620..d6baa29 100644
--- a/test/TimeZoneConverter.Tests/DataVerificationTests.Iana_To_Rails.verified.txt
+++ b/test/TimeZoneConverter.Tests/DataVerificationTests.Iana_To_Rails.verified.txt
@@ -1,6 +1,10 @@
 {
-  Africa/Abidjan: null,
-  Africa/Accra: null,
+  Africa/Abidjan: [
+    Africa/Abidjan
+  ],
+  Africa/Accra: [
+    Africa/Accra
+  ],
   Africa/Addis_Ababa: [
     Nairobi
   ],
@@ -13,14 +17,24 @@
   Africa/Asmera: [
     Nairobi
   ],
-  Africa/Bamako: null,
-  Africa/Bangui: null,
-  Africa/Banjul: null,
-  Africa/Bissau: null,
+  Africa/Bamako: [
+    Africa/Bamako
+  ],
+  Africa/Bangui: [
+    Africa/Bangui
+  ],
+  Africa/Banjul: [
+    Africa/Banjul
+  ],
+  Africa/Bissau: [
+    Africa/Bissau
+  ],
   Africa/Blantyre: [
     Pretoria
   ],
-  Africa/Brazzaville: null,
+  Africa/Brazzaville: [
+    Africa/Brazzaville
+  ],
   Africa/Bujumbura: [
     Pretoria
   ],
@@ -33,19 +47,27 @@
   Africa/Ceuta: [
     Madrid
   ],
-  Africa/Conakry: null,
-  Africa/Dakar: null,
+  Africa/Conakry: [
+    Africa/Conakry
+  ],
+  Africa/Dakar: [
+    Africa/Dakar
+  ],
   Africa/Dar_es_Salaam: [
     Nairobi
   ],
   Africa/Djibouti: [
     Nairobi
   ],
-  Africa/Douala: null,
+  Africa/Douala: [
+    Africa/Douala
+  ],
   Africa/El_Aaiun: [
     Casablanca
   ],
-  Africa/Freetown: null,
+  Africa/Freetown: [
+    Africa/Freetown
+  ],
   Africa/Gaborone: [
     Pretoria
   ],
@@ -55,26 +77,42 @@
   Africa/Johannesburg: [
     Pretoria
   ],
-  Africa/Juba: null,
+  Africa/Juba: [
+    Africa/Juba
+  ],
   Africa/Kampala: [
     Nairobi
   ],
-  Africa/Khartoum: null,
+  Africa/Khartoum: [
+    Africa/Khartoum
+  ],
   Africa/Kigali: [
     Harare
   ],
-  Africa/Kinshasa: null,
-  Africa/Lagos: null,
-  Africa/Libreville: null,
-  Africa/Lome: null,
-  Africa/Luanda: null,
+  Africa/Kinshasa: [
+    Africa/Kinshasa
+  ],
+  Africa/Lagos: [
+    Africa/Lagos
+  ],
+  Africa/Libreville: [
+    Africa/Libreville
+  ],
+  Africa/Lome: [
+    Africa/Lome
+  ],
+  Africa/Luanda: [
+    Africa/Luanda
+  ],
   Africa/Lubumbashi: [
     Harare
   ],
   Africa/Lusaka: [
     Harare
   ],
-  Africa/Malabo: null,
+  Africa/Malabo: [
+    Africa/Malabo
+  ],
   Africa/Maputo: [
     Harare
   ],
@@ -93,17 +131,39 @@
   Africa/Nairobi: [
     Nairobi
   ],
-  Africa/Ndjamena: null,
-  Africa/Niamey: null,
-  Africa/Nouakchott: null,
-  Africa/Ouagadougou: null,
-  Africa/Porto-Novo: null,
-  Africa/Sao_Tome: null,
-  Africa/Timbuktu: null,
-  Africa/Tripoli: null,
-  Africa/Tunis: null,
-  Africa/Windhoek: null,
-  America/Adak: null,
+  Africa/Ndjamena: [
+    Africa/Ndjamena
+  ],
+  Africa/Niamey: [
+    Africa/Niamey
+  ],
+  Africa/Nouakchott: [
+    Africa/Nouakchott
+  ],
+  Africa/Ouagadougou: [
+    Africa/Ouagadougou
+  ],
+  Africa/Porto-Novo: [
+    Africa/Porto-Novo
+  ],
+  Africa/Sao_Tome: [
+    Africa/Sao_Tome
+  ],
+  Africa/Timbuktu: [
+    Africa/Timbuktu
+  ],
+  Africa/Tripoli: [
+    Africa/Tripoli
+  ],
+  Africa/Tunis: [
+    Africa/Tunis
+  ],
+  Africa/Windhoek: [
+    Africa/Windhoek
+  ],
+  America/Adak: [
+    America/Adak
+  ],
   America/Anchorage: [
     Alaska
   ],
@@ -113,7 +173,9 @@
   America/Antigua: [
     Puerto Rico
   ],
-  America/Araguaina: null,
+  America/Araguaina: [
+    America/Araguaina
+  ],
   America/Argentina/Buenos_Aires: [
     Buenos Aires
   ],
@@ -162,8 +224,12 @@
   America/Atikokan: [
     Bogota
   ],
-  America/Atka: null,
-  America/Bahia: null,
+  America/Atka: [
+    America/Atka
+  ],
+  America/Bahia: [
+    America/Bahia
+  ],
   America/Bahia_Banderas: [
     Guadalajara,
     Mexico City
@@ -171,7 +237,9 @@
   America/Barbados: [
     La Paz
   ],
-  America/Belem: null,
+  America/Belem: [
+    America/Belem
+  ],
   America/Belize: [
     Central America
   ],
@@ -193,15 +261,21 @@
   America/Cambridge_Bay: [
     Mountain Time (US & Canada)
   ],
-  America/Campo_Grande: null,
-  America/Cancun: null,
+  America/Campo_Grande: [
+    America/Campo_Grande
+  ],
+  America/Cancun: [
+    America/Cancun
+  ],
   America/Caracas: [
     Caracas
   ],
   America/Catamarca: [
     Buenos Aires
   ],
-  America/Cayenne: null,
+  America/Cayenne: [
+    America/Cayenne
+  ],
   America/Cayman: [
     Bogota
   ],
@@ -223,17 +297,23 @@
   America/Costa_Rica: [
     Central America
   ],
-  America/Coyhaique: null,
+  America/Coyhaique: [
+    America/Coyhaique
+  ],
   America/Creston: [
     Arizona
   ],
-  America/Cuiaba: null,
+  America/Cuiaba: [
+    America/Cuiaba
+  ],
   America/Curacao: [
     Puerto Rico
   ],
-  America/Danmarkshavn: null,
+  America/Danmarkshavn: [
+    America/Danmarkshavn
+  ],
   America/Dawson: [
-    Arizona
+    America/Dawson
   ],
   America/Dawson_Creek: [
     Arizona
@@ -265,7 +345,9 @@
   America/Fort_Wayne: [
     Indiana (East)
   ],
-  America/Fortaleza: null,
+  America/Fortaleza: [
+    America/Fortaleza
+  ],
   America/Glace_Bay: [
     Atlantic Time (Canada)
   ],
@@ -275,7 +357,9 @@
   America/Goose_Bay: [
     Atlantic Time (Canada)
   ],
-  America/Grand_Turk: null,
+  America/Grand_Turk: [
+    America/Grand_Turk
+  ],
   America/Grenada: [
     Puerto Rico
   ],
@@ -294,7 +378,9 @@
   America/Halifax: [
     Atlantic Time (Canada)
   ],
-  America/Havana: null,
+  America/Havana: [
+    America/Havana
+  ],
   America/Hermosillo: [
     Arizona
   ],
@@ -368,7 +454,9 @@
   America/Lower_Princes: [
     Puerto Rico
   ],
-  America/Maceio: null,
+  America/Maceio: [
+    America/Maceio
+  ],
   America/Managua: [
     Central America
   ],
@@ -404,7 +492,9 @@
     Guadalajara,
     Mexico City
   ],
-  America/Miquelon: null,
+  America/Miquelon: [
+    America/Miquelon
+  ],
   America/Moncton: [
     Atlantic Time (Canada)
   ],
@@ -432,7 +522,9 @@
   America/Nome: [
     Alaska
   ],
-  America/Noronha: null,
+  America/Noronha: [
+    America/Noronha
+  ],
   America/North_Dakota/Beulah: [
     Central Time (US & Canada)
   ],
@@ -454,11 +546,15 @@
   America/Pangnirtung: [
     Eastern Time (US & Canada)
   ],
-  America/Paramaribo: null,
+  America/Paramaribo: [
+    America/Paramaribo
+  ],
   America/Phoenix: [
     Arizona
   ],
-  America/Port-au-Prince: null,
+  America/Port-au-Prince: [
+    America/Port-au-Prince
+  ],
   America/Port_of_Spain: [
     Puerto Rico
   ],
@@ -471,14 +567,18 @@
   America/Puerto_Rico: [
     Puerto Rico
   ],
-  America/Punta_Arenas: null,
+  America/Punta_Arenas: [
+    America/Punta_Arenas
+  ],
   America/Rainy_River: [
     Central Time (US & Canada)
   ],
   America/Rankin_Inlet: [
     Central Time (US & Canada)
   ],
-  America/Recife: null,
+  America/Recife: [
+    America/Recife
+  ],
   America/Regina: [
     Saskatchewan
   ],
@@ -494,7 +594,9 @@
   America/Santa_Isabel: [
     Tijuana
   ],
-  America/Santarem: null,
+  America/Santarem: [
+    America/Santarem
+  ],
   America/Santiago: [
     Santiago
   ],
@@ -559,7 +661,7 @@
     Puerto Rico
   ],
   America/Whitehorse: [
-    Arizona
+    America/Whitehorse
   ],
   America/Winnipeg: [
     Central Time (US & Canada)
@@ -590,8 +692,12 @@
     Auckland,
     Wellington
   ],
-  Antarctica/Palmer: null,
-  Antarctica/Rothera: null,
+  Antarctica/Palmer: [
+    Antarctica/Palmer
+  ],
+  Antarctica/Rothera: [
+    Antarctica/Rothera
+  ],
   Antarctica/South_Pole: [
     Auckland,
     Wellington
@@ -599,8 +705,12 @@
   Antarctica/Syowa: [
     Riyadh
   ],
-  Antarctica/Troll: null,
-  Antarctica/Vostok: null,
+  Antarctica/Troll: [
+    Antarctica/Troll
+  ],
+  Antarctica/Vostok: [
+    Antarctica/Vostok
+  ],
   Arctic/Longyearbyen: [
     Berlin
   ],
@@ -611,7 +721,9 @@
     Almaty,
     Astana
   ],
-  Asia/Amman: null,
+  Asia/Amman: [
+    Asia/Amman
+  ],
   Asia/Anadyr: [
     Kamchatka
   ],
@@ -646,9 +758,15 @@
     Bangkok,
     Hanoi
   ],
-  Asia/Barnaul: null,
-  Asia/Beirut: null,
-  Asia/Bishkek: null,
+  Asia/Barnaul: [
+    Asia/Barnaul
+  ],
+  Asia/Beirut: [
+    Asia/Beirut
+  ],
+  Asia/Bishkek: [
+    Asia/Bishkek
+  ],
   Asia/Brunei: [
     Kuala Lumpur
   ],
@@ -658,7 +776,9 @@
     Mumbai,
     New Delhi
   ],
-  Asia/Chita: null,
+  Asia/Chita: [
+    Asia/Chita
+  ],
   Asia/Choibalsan: [
     Ulaanbaatar
   ],
@@ -674,7 +794,9 @@
   Asia/Dacca: [
     Dhaka
   ],
-  Asia/Damascus: null,
+  Asia/Damascus: [
+    Asia/Damascus
+  ],
   Asia/Dhaka: [
     Dhaka
   ],
@@ -693,11 +815,15 @@
   Asia/Famagusta: [
     Bucharest
   ],
-  Asia/Gaza: null,
+  Asia/Gaza: [
+    Asia/Gaza
+  ],
   Asia/Harbin: [
     Beijing
   ],
-  Asia/Hebron: null,
+  Asia/Hebron: [
+    Asia/Hebron
+  ],
   Asia/Ho_Chi_Minh: [
     Bangkok,
     Hanoi
@@ -705,7 +831,9 @@
   Asia/Hong_Kong: [
     Hong Kong
   ],
-  Asia/Hovd: null,
+  Asia/Hovd: [
+    Asia/Hovd
+  ],
   Asia/Irkutsk: [
     Irkutsk
   ],
@@ -791,7 +919,9 @@
   Asia/Novosibirsk: [
     Novosibirsk
   ],
-  Asia/Omsk: null,
+  Asia/Omsk: [
+    Asia/Omsk
+  ],
   Asia/Oral: [
     Almaty,
     Astana
@@ -803,7 +933,9 @@
   Asia/Pontianak: [
     Jakarta
   ],
-  Asia/Pyongyang: null,
+  Asia/Pyongyang: [
+    Asia/Pyongyang
+  ],
   Asia/Qatar: [
     Riyadh
   ],
@@ -811,7 +943,9 @@
     Almaty,
     Astana
   ],
-  Asia/Qyzylorda: null,
+  Asia/Qyzylorda: [
+    Asia/Qyzylorda
+  ],
   Asia/Rangoon: [
     Rangoon
   ],
@@ -822,7 +956,9 @@
     Bangkok,
     Hanoi
   ],
-  Asia/Sakhalin: null,
+  Asia/Sakhalin: [
+    Asia/Sakhalin
+  ],
   Asia/Samarkand: [
     Tashkent
   ],
@@ -864,7 +1000,9 @@
     Sapporo,
     Tokyo
   ],
-  Asia/Tomsk: null,
+  Asia/Tomsk: [
+    Asia/Tomsk
+  ],
   Asia/Ujung_Pandang: [
     Singapore
   ],
@@ -926,12 +1064,18 @@
   Atlantic/Madeira: [
     Lisbon
   ],
-  Atlantic/Reykjavik: null,
+  Atlantic/Reykjavik: [
+    Atlantic/Reykjavik
+  ],
   Atlantic/South_Georgia: [
     Mid-Atlantic
   ],
-  Atlantic/St_Helena: null,
-  Atlantic/Stanley: null,
+  Atlantic/St_Helena: [
+    Atlantic/St_Helena
+  ],
+  Atlantic/Stanley: [
+    Atlantic/Stanley
+  ],
   Australia/ACT: [
     Sydney
   ],
@@ -953,15 +1097,21 @@
   Australia/Darwin: [
     Darwin
   ],
-  Australia/Eucla: null,
+  Australia/Eucla: [
+    Australia/Eucla
+  ],
   Australia/Hobart: [
     Hobart
   ],
-  Australia/LHI: null,
+  Australia/LHI: [
+    Australia/LHI
+  ],
   Australia/Lindeman: [
     Brisbane
   ],
-  Australia/Lord_Howe: null,
+  Australia/Lord_Howe: [
+    Australia/Lord_Howe
+  ],
   Australia/Melbourne: [
     Melbourne
   ],
@@ -998,7 +1148,9 @@
   Brazil/Acre: [
     Bogota
   ],
-  Brazil/DeNoronha: null,
+  Brazil/DeNoronha: [
+    Brazil/DeNoronha
+  ],
   Brazil/East: [
     Brasilia
   ],
@@ -1033,13 +1185,17 @@
     Saskatchewan
   ],
   Canada/Yukon: [
-    Arizona
+    Canada/Yukon
   ],
   Chile/Continental: [
     Santiago
   ],
-  Chile/EasterIsland: null,
-  Cuba: null,
+  Chile/EasterIsland: [
+    Chile/EasterIsland
+  ],
+  Cuba: [
+    Cuba
+  ],
   EET: [
     Athens
   ],
@@ -1065,14 +1221,20 @@
     Cape Verde Is.
   ],
   Etc/GMT+10: [
-    Hawaii
+    -10:00
+  ],
+  Etc/GMT+11: [
+    -11:00
   ],
-  Etc/GMT+11: null,
   Etc/GMT+12: [
-    International Date Line West
+    -12:00
+  ],
+  Etc/GMT+2: [
+    Etc/GMT+2
+  ],
+  Etc/GMT+3: [
+    Etc/GMT+3
   ],
-  Etc/GMT+2: null,
-  Etc/GMT+3: null,
   Etc/GMT+4: [
     La Paz
   ],
@@ -1085,21 +1247,33 @@
   Etc/GMT+7: [
     Arizona
   ],
-  Etc/GMT+8: null,
-  Etc/GMT+9: null,
+  Etc/GMT+8: [
+    Etc/GMT+8
+  ],
+  Etc/GMT+9: [
+    Etc/GMT+9
+  ],
   Etc/GMT-0: [
     UTC
   ],
-  Etc/GMT-1: null,
+  Etc/GMT-1: [
+    Etc/GMT-1
+  ],
   Etc/GMT-10: [
-    Port Moresby
+    +10:00
   ],
   Etc/GMT-11: [
-    Solomon Is.
+    +11:00
+  ],
+  Etc/GMT-12: [
+    +12:00
+  ],
+  Etc/GMT-13: [
+    +13:00
+  ],
+  Etc/GMT-14: [
+    +14:00
   ],
-  Etc/GMT-12: null,
-  Etc/GMT-13: null,
-  Etc/GMT-14: null,
   Etc/GMT-2: [
     Pretoria
   ],
@@ -1113,7 +1287,9 @@
   Etc/GMT-5: [
     Tashkent
   ],
-  Etc/GMT-6: null,
+  Etc/GMT-6: [
+    Etc/GMT-6
+  ],
   Etc/GMT-7: [
     Bangkok,
     Hanoi
@@ -1150,7 +1326,9 @@
   Europe/Andorra: [
     Berlin
   ],
-  Europe/Astrakhan: null,
+  Europe/Astrakhan: [
+    Europe/Astrakhan
+  ],
   Europe/Athens: [
     Athens
   ],
@@ -1180,7 +1358,9 @@
     Bern,
     Zurich
   ],
-  Europe/Chisinau: null,
+  Europe/Chisinau: [
+    Europe/Chisinau
+  ],
   Europe/Copenhagen: [
     Copenhagen
   ],
@@ -1283,7 +1463,9 @@
   Europe/Sarajevo: [
     Sarajevo
   ],
-  Europe/Saratov: null,
+  Europe/Saratov: [
+    Europe/Saratov
+  ],
   Europe/Simferopol: [
     Moscow,
     St. Petersburg
@@ -1303,8 +1485,12 @@
   Europe/Tirane: [
     Budapest
   ],
-  Europe/Tiraspol: null,
-  Europe/Ulyanovsk: null,
+  Europe/Tiraspol: [
+    Europe/Tiraspol
+  ],
+  Europe/Ulyanovsk: [
+    Europe/Ulyanovsk
+  ],
   Europe/Uzhgorod: [
     Kyiv
   ],
@@ -1366,11 +1552,15 @@
   Hongkong: [
     Hong Kong
   ],
-  Iceland: null,
+  Iceland: [
+    Iceland
+  ],
   Indian/Antananarivo: [
     Nairobi
   ],
-  Indian/Chagos: null,
+  Indian/Chagos: [
+    Indian/Chagos
+  ],
   Indian/Christmas: [
     Bangkok,
     Hanoi
@@ -1391,7 +1581,9 @@
   Indian/Maldives: [
     Tashkent
   ],
-  Indian/Mauritius: null,
+  Indian/Mauritius: [
+    Indian/Mauritius
+  ],
   Indian/Mayotte: [
     Nairobi
   ],
@@ -1416,7 +1608,9 @@
   Kwajalein: [
     Marshall Is.
   ],
-  Libya: null,
+  Libya: [
+    Libya
+  ],
   MET: [
     Brussels
   ],
@@ -1459,29 +1653,39 @@
     Auckland,
     Wellington
   ],
-  Pacific/Bougainville: null,
+  Pacific/Bougainville: [
+    Pacific/Bougainville
+  ],
   Pacific/Chatham: [
     Chatham Is.
   ],
   Pacific/Chuuk: [
     Port Moresby
   ],
-  Pacific/Easter: null,
+  Pacific/Easter: [
+    Pacific/Easter
+  ],
   Pacific/Efate: [
     Solomon Is.
   ],
-  Pacific/Enderbury: null,
+  Pacific/Enderbury: [
+    Pacific/Enderbury
+  ],
   Pacific/Fakaofo: [
     Tokelau Is.
   ],
   Pacific/Fiji: [
     Fiji
   ],
-  Pacific/Funafuti: null,
+  Pacific/Funafuti: [
+    Pacific/Funafuti
+  ],
   Pacific/Galapagos: [
     Central America
   ],
-  Pacific/Gambier: null,
+  Pacific/Gambier: [
+    Pacific/Gambier
+  ],
   Pacific/Guadalcanal: [
     Solomon Is.
   ],
@@ -1494,8 +1698,12 @@
   Pacific/Johnston: [
     Hawaii
   ],
-  Pacific/Kanton: null,
-  Pacific/Kiritimati: null,
+  Pacific/Kanton: [
+    Pacific/Kanton
+  ],
+  Pacific/Kiritimati: [
+    Pacific/Kiritimati
+  ],
   Pacific/Kosrae: [
     Solomon Is.
   ],
@@ -1505,13 +1713,21 @@
   Pacific/Majuro: [
     Marshall Is.
   ],
-  Pacific/Marquesas: null,
+  Pacific/Marquesas: [
+    Pacific/Marquesas
+  ],
   Pacific/Midway: [
     Midway Island
   ],
-  Pacific/Nauru: null,
-  Pacific/Niue: null,
-  Pacific/Norfolk: null,
+  Pacific/Nauru: [
+    Pacific/Nauru
+  ],
+  Pacific/Niue: [
+    Pacific/Niue
+  ],
+  Pacific/Norfolk: [
+    Pacific/Norfolk
+  ],
   Pacific/Noumea: [
     New Caledonia
   ],
@@ -1523,7 +1739,9 @@
     Sapporo,
     Tokyo
   ],
-  Pacific/Pitcairn: null,
+  Pacific/Pitcairn: [
+    Pacific/Pitcairn
+  ],
   Pacific/Pohnpei: [
     Solomon Is.
   ],
@@ -1587,7 +1805,9 @@
   US/Alaska: [
     Alaska
   ],
-  US/Aleutian: null,
+  US/Aleutian: [
+    US/Aleutian
+  ],
   US/Arizona: [
     Arizona
   ],
diff --git a/test/TimeZoneConverter.Tests/DataVerificationTests.Windows_To_Rails.verified.txt b/test/TimeZoneConverter.Tests/DataVerificationTests.Windows_To_Rails.verified.txt
index d0d95fc..4972e63 100644
--- a/test/TimeZoneConverter.Tests/DataVerificationTests.Windows_To_Rails.verified.txt
+++ b/test/TimeZoneConverter.Tests/DataVerificationTests.Windows_To_Rails.verified.txt
@@ -11,8 +11,12 @@
   Alaskan Standard Time: [
     Alaska
   ],
-  Aleutian Standard Time: null,
-  Altai Standard Time: null,
+  Aleutian Standard Time: [
+    America/Adak
+  ],
+  Altai Standard Time: [
+    Asia/Barnaul
+  ],
   Arab Standard Time: [
     Riyadh
   ],
@@ -26,25 +30,33 @@
   Argentina Standard Time: [
     Buenos Aires
   ],
-  Astrakhan Standard Time: null,
+  Astrakhan Standard Time: [
+    Europe/Astrakhan
+  ],
   Atlantic Standard Time: [
     Atlantic Time (Canada)
   ],
-  Aus Central W. Standard Time: null,
+  Aus Central W. Standard Time: [
+    Australia/Eucla
+  ],
   Azerbaijan Standard Time: [
     Baku
   ],
   Azores Standard Time: [
     Azores
   ],
-  Bahia Standard Time: null,
+  Bahia Standard Time: [
+    America/Bahia
+  ],
   Bangladesh Standard Time: [
     Dhaka
   ],
   Belarus Standard Time: [
     Minsk
   ],
-  Bougainville Standard Time: null,
+  Bougainville Standard Time: [
+    Pacific/Bougainville
+  ],
   Canada Central Standard Time: [
     Saskatchewan
   ],
@@ -60,8 +72,12 @@
   Central America Standard Time: [
     Central America
   ],
-  Central Asia Standard Time: null,
-  Central Brazilian Standard Time: null,
+  Central Asia Standard Time: [
+    Asia/Bishkek
+  ],
+  Central Brazilian Standard Time: [
+    America/Cuiaba
+  ],
   Central Europe Standard Time: [
     Budapest
   ],
@@ -84,7 +100,9 @@
   China Standard Time: [
     Beijing
   ],
-  Cuba Standard Time: null,
+  Cuba Standard Time: [
+    America/Havana
+  ],
   Dateline Standard Time: [
     International Date Line West
   ],
@@ -94,15 +112,21 @@
   E. Australia Standard Time: [
     Brisbane
   ],
-  E. Europe Standard Time: null,
+  E. Europe Standard Time: [
+    Europe/Chisinau
+  ],
   E. South America Standard Time: [
     Brasilia
   ],
-  Easter Island Standard Time: null,
+  Easter Island Standard Time: [
+    Pacific/Easter
+  ],
   Eastern Standard Time: [
     Eastern Time (US & Canada)
   ],
-  Eastern Standard Time (Mexico): null,
+  Eastern Standard Time (Mexico): [
+    America/Cancun
+  ],
   Egypt Standard Time: [
     Cairo
   ],
@@ -128,8 +152,12 @@
   Greenland Standard Time: [
     Greenland
   ],
-  Greenwich Standard Time: null,
-  Haiti Standard Time: null,
+  Greenwich Standard Time: [
+    Africa/Abidjan
+  ],
+  Haiti Standard Time: [
+    America/Port-au-Prince
+  ],
   Hawaiian Standard Time: [
     Hawaii
   ],
@@ -145,23 +173,39 @@
   Israel Standard Time: [
     Jerusalem
   ],
-  Jordan Standard Time: null,
+  Jordan Standard Time: [
+    Asia/Amman
+  ],
   Kaliningrad Standard Time: [
     Kaliningrad
   ],
   Korea Standard Time: [
     Seoul
   ],
-  Libya Standard Time: null,
-  Line Islands Standard Time: null,
-  Lord Howe Standard Time: null,
+  Libya Standard Time: [
+    Africa/Tripoli
+  ],
+  Line Islands Standard Time: [
+    Pacific/Kiritimati
+  ],
+  Lord Howe Standard Time: [
+    Australia/Lord_Howe
+  ],
   Magadan Standard Time: [
     Magadan
   ],
-  Magallanes Standard Time: null,
-  Marquesas Standard Time: null,
-  Mauritius Standard Time: null,
-  Middle East Standard Time: null,
+  Magallanes Standard Time: [
+    America/Punta_Arenas
+  ],
+  Marquesas Standard Time: [
+    Pacific/Marquesas
+  ],
+  Mauritius Standard Time: [
+    Indian/Mauritius
+  ],
+  Middle East Standard Time: [
+    Asia/Beirut
+  ],
   Montevideo Standard Time: [
     Montevideo
   ],
@@ -180,7 +224,9 @@
   N. Central Asia Standard Time: [
     Novosibirsk
   ],
-  Namibia Standard Time: null,
+  Namibia Standard Time: [
+    Africa/Windhoek
+  ],
   Nepal Standard Time: [
     Kathmandu
   ],
@@ -191,15 +237,21 @@
   Newfoundland Standard Time: [
     Newfoundland
   ],
-  Norfolk Standard Time: null,
+  Norfolk Standard Time: [
+    Pacific/Norfolk
+  ],
   North Asia East Standard Time: [
     Irkutsk
   ],
   North Asia Standard Time: [
     Krasnoyarsk
   ],
-  North Korea Standard Time: null,
-  Omsk Standard Time: null,
+  North Korea Standard Time: [
+    Asia/Pyongyang
+  ],
+  Omsk Standard Time: [
+    Asia/Omsk
+  ],
   Pacific SA Standard Time: [
     Santiago
   ],
@@ -216,7 +268,9 @@
   Paraguay Standard Time: [
     Asuncion
   ],
-  Qyzylorda Standard Time: null,
+  Qyzylorda Standard Time: [
+    Asia/Qyzylorda
+  ],
   Romance Standard Time: [
     Paris
   ],
@@ -233,7 +287,9 @@
     Moscow,
     St. Petersburg
   ],
-  SA Eastern Standard Time: null,
+  SA Eastern Standard Time: [
+    America/Cayenne
+  ],
   SA Pacific Standard Time: [
     Bogota
   ],
@@ -244,46 +300,68 @@
     Bangkok,
     Hanoi
   ],
-  Saint Pierre Standard Time: null,
-  Sakhalin Standard Time: null,
+  Saint Pierre Standard Time: [
+    America/Miquelon
+  ],
+  Sakhalin Standard Time: [
+    Asia/Sakhalin
+  ],
   Samoa Standard Time: [
     Samoa
   ],
-  Sao Tome Standard Time: null,
-  Saratov Standard Time: null,
+  Sao Tome Standard Time: [
+    Africa/Sao_Tome
+  ],
+  Saratov Standard Time: [
+    Europe/Saratov
+  ],
   Singapore Standard Time: [
     Singapore
   ],
   South Africa Standard Time: [
     Pretoria
   ],
-  South Sudan Standard Time: null,
+  South Sudan Standard Time: [
+    Africa/Juba
+  ],
   Sri Lanka Standard Time: [
     Sri Jayawardenepura
   ],
-  Sudan Standard Time: null,
-  Syria Standard Time: null,
+  Sudan Standard Time: [
+    Africa/Khartoum
+  ],
+  Syria Standard Time: [
+    Asia/Damascus
+  ],
   Taipei Standard Time: [
     Taipei
   ],
   Tasmania Standard Time: [
     Hobart
   ],
-  Tocantins Standard Time: null,
+  Tocantins Standard Time: [
+    America/Araguaina
+  ],
   Tokyo Standard Time: [
     Osaka,
     Sapporo,
     Tokyo
   ],
-  Tomsk Standard Time: null,
+  Tomsk Standard Time: [
+    Asia/Tomsk
+  ],
   Tonga Standard Time: [
     Nuku'alofa
   ],
-  Transbaikal Standard Time: null,
+  Transbaikal Standard Time: [
+    Asia/Chita
+  ],
   Turkey Standard Time: [
     Istanbul
   ],
-  Turks And Caicos Standard Time: null,
+  Turks And Caicos Standard Time: [
+    America/Grand_Turk
+  ],
   US Eastern Standard Time: [
     Indiana (East)
   ],
@@ -293,12 +371,24 @@
   UTC: [
     UTC
   ],
-  UTC+12: null,
-  UTC+13: null,
-  UTC-02: null,
-  UTC-08: null,
-  UTC-09: null,
-  UTC-11: null,
+  UTC+12: [
+    +12:00
+  ],
+  UTC+13: [
+    +13:00
+  ],
+  UTC-02: [
+    Etc/GMT+2
+  ],
+  UTC-08: [
+    Etc/GMT+8
+  ],
+  UTC-09: [
+    Etc/GMT+9
+  ],
+  UTC-11: [
+    -11:00
+  ],
   Ulaanbaatar Standard Time: [
     Ulaanbaatar
   ],
@@ -314,15 +404,21 @@
   W. Australia Standard Time: [
     Perth
   ],
-  W. Central Africa Standard Time: null,
+  W. Central Africa Standard Time: [
+    Africa/Lagos
+  ],
   W. Europe Standard Time: [
     Berlin
   ],
-  W. Mongolia Standard Time: null,
+  W. Mongolia Standard Time: [
+    Asia/Hovd
+  ],
   West Asia Standard Time: [
     Tashkent
   ],
-  West Bank Standard Time: null,
+  West Bank Standard Time: [
+    Asia/Hebron
+  ],
   West Pacific Standard Time: [
     Port Moresby
   ],
@@ -330,6 +426,6 @@
     Yakutsk
   ],
   Yukon Standard Time: [
-    Arizona
+    America/Whitehorse
   ]
 }
\ No newline at end of file
diff --git a/test/TimeZoneConverter.Tests/DataVerificationTests.Windows_To_Rails_Regional.verified.txt b/test/TimeZoneConverter.Tests/DataVerificationTests.Windows_To_Rails_Regional.verified.txt
index ff40352..309c4a2 100644
--- a/test/TimeZoneConverter.Tests/DataVerificationTests.Windows_To_Rails_Regional.verified.txt
+++ b/test/TimeZoneConverter.Tests/DataVerificationTests.Windows_To_Rails_Regional.verified.txt
@@ -11,8 +11,12 @@
   (Alaskan Standard Time, 001): [
     Alaska
   ],
-  (Aleutian Standard Time, 001): null,
-  (Altai Standard Time, 001): null,
+  (Aleutian Standard Time, 001): [
+    America/Adak
+  ],
+  (Altai Standard Time, 001): [
+    Asia/Barnaul
+  ],
   (Arab Standard Time, 001): [
     Riyadh
   ],
@@ -29,25 +33,33 @@
   (Argentina Standard Time, 001): [
     Buenos Aires
   ],
-  (Astrakhan Standard Time, 001): null,
+  (Astrakhan Standard Time, 001): [
+    Europe/Astrakhan
+  ],
   (Atlantic Standard Time, 001): [
     Atlantic Time (Canada)
   ],
-  (Aus Central W. Standard Time, 001): null,
+  (Aus Central W. Standard Time, 001): [
+    Australia/Eucla
+  ],
   (Azerbaijan Standard Time, 001): [
     Baku
   ],
   (Azores Standard Time, 001): [
     Azores
   ],
-  (Bahia Standard Time, 001): null,
+  (Bahia Standard Time, 001): [
+    America/Bahia
+  ],
   (Bangladesh Standard Time, 001): [
     Dhaka
   ],
   (Belarus Standard Time, 001): [
     Minsk
   ],
-  (Bougainville Standard Time, 001): null,
+  (Bougainville Standard Time, 001): [
+    Pacific/Bougainville
+  ],
   (Canada Central Standard Time, 001): [
     Saskatchewan
   ],
@@ -63,8 +75,21 @@
   (Central America Standard Time, 001): [
     Central America
   ],
-  (Central Asia Standard Time, 001): null,
-  (Central Brazilian Standard Time, 001): null,
+  (Central Asia Standard Time, 001): [
+    Asia/Bishkek
+  ],
+  (Central Asia Standard Time, CN): [
+    Urumqi
+  ],
+  (Central Asia Standard Time, DG): [
+    Indian/Chagos
+  ],
+  (Central Asia Standard Time, IO): [
+    Indian/Chagos
+  ],
+  (Central Brazilian Standard Time, 001): [
+    America/Cuiaba
+  ],
   (Central Europe Standard Time, 001): [
     Budapest
   ],
@@ -120,7 +145,9 @@
   (China Standard Time, HK): [
     Hong Kong
   ],
-  (Cuba Standard Time, 001): null,
+  (Cuba Standard Time, 001): [
+    America/Havana
+  ],
   (Dateline Standard Time, 001): [
     International Date Line West
   ],
@@ -130,12 +157,18 @@
   (E. Australia Standard Time, 001): [
     Brisbane
   ],
-  (E. Europe Standard Time, 001): null,
+  (E. Europe Standard Time, 001): [
+    Europe/Chisinau
+  ],
   (E. South America Standard Time, 001): [
     Brasilia
   ],
-  (Easter Island Standard Time, 001): null,
-  (Eastern Standard Time (Mexico), 001): null,
+  (Easter Island Standard Time, 001): [
+    Pacific/Easter
+  ],
+  (Eastern Standard Time (Mexico), 001): [
+    America/Cancun
+  ],
   (Eastern Standard Time, 001): [
     Eastern Time (US & Canada)
   ],
@@ -191,8 +224,51 @@
   (Greenland Standard Time, 001): [
     Greenland
   ],
-  (Greenwich Standard Time, 001): null,
-  (Haiti Standard Time, 001): null,
+  (Greenwich Standard Time, 001): [
+    Africa/Abidjan
+  ],
+  (Greenwich Standard Time, BF): [
+    Africa/Ouagadougou
+  ],
+  (Greenwich Standard Time, GH): [
+    Africa/Accra
+  ],
+  (Greenwich Standard Time, GL): [
+    America/Danmarkshavn
+  ],
+  (Greenwich Standard Time, GM): [
+    Africa/Banjul
+  ],
+  (Greenwich Standard Time, GN): [
+    Africa/Conakry
+  ],
+  (Greenwich Standard Time, GW): [
+    Africa/Bissau
+  ],
+  (Greenwich Standard Time, LR): [
+    Monrovia
+  ],
+  (Greenwich Standard Time, ML): [
+    Africa/Bamako
+  ],
+  (Greenwich Standard Time, MR): [
+    Africa/Nouakchott
+  ],
+  (Greenwich Standard Time, SH): [
+    Atlantic/St_Helena
+  ],
+  (Greenwich Standard Time, SL): [
+    Africa/Freetown
+  ],
+  (Greenwich Standard Time, SN): [
+    Africa/Dakar
+  ],
+  (Greenwich Standard Time, TG): [
+    Africa/Lome
+  ],
+  (Haiti Standard Time, 001): [
+    America/Port-au-Prince
+  ],
   (Hawaiian Standard Time, 001): [
     Hawaii
   ],
@@ -208,23 +284,47 @@
   (Israel Standard Time, 001): [
     Jerusalem
   ],
-  (Jordan Standard Time, 001): null,
+  (Jordan Standard Time, 001): [
+    Asia/Amman
+  ],
   (Kaliningrad Standard Time, 001): [
     Kaliningrad
   ],
   (Korea Standard Time, 001): [
     Seoul
   ],
-  (Libya Standard Time, 001): null,
-  (Line Islands Standard Time, 001): null,
-  (Lord Howe Standard Time, 001): null,
+  (Libya Standard Time, 001): [
+    Africa/Tripoli
+  ],
+  (Line Islands Standard Time, 001): [
+    Pacific/Kiritimati
+  ],
+  (Lord Howe Standard Time, 001): [
+    Australia/Lord_Howe
+  ],
   (Magadan Standard Time, 001): [
     Magadan
   ],
-  (Magallanes Standard Time, 001): null,
-  (Marquesas Standard Time, 001): null,
-  (Mauritius Standard Time, 001): null,
-  (Middle East Standard Time, 001): null,
+  (Magallanes Standard Time, 001): [
+    America/Punta_Arenas
+  ],
+  (Marquesas Standard Time, 001): [
+    Pacific/Marquesas
+  ],
+  (Mauritius Standard Time, 001): [
+    Indian/Mauritius
+  ],
+  (Mauritius Standard Time, RE): [
+    Abu Dhabi,
+    Muscat
+  ],
+  (Mauritius Standard Time, SC): [
+    Abu Dhabi,
+    Muscat
+  ],
+  (Middle East Standard Time, 001): [
+    Asia/Beirut
+  ],
   (Montevideo Standard Time, 001): [
     Montevideo
   ],
@@ -243,7 +343,9 @@
   (N. Central Asia Standard Time, 001): [
     Novosibirsk
   ],
-  (Namibia Standard Time, 001): null,
+  (Namibia Standard Time, 001): [
+    Africa/Windhoek
+  ],
   (Nepal Standard Time, 001): [
     Kathmandu
   ],
@@ -254,15 +356,21 @@
   (Newfoundland Standard Time, 001): [
     Newfoundland
   ],
-  (Norfolk Standard Time, 001): null,
+  (Norfolk Standard Time, 001): [
+    Pacific/Norfolk
+  ],
   (North Asia East Standard Time, 001): [
     Irkutsk
   ],
   (North Asia Standard Time, 001): [
     Krasnoyarsk
   ],
-  (North Korea Standard Time, 001): null,
-  (Omsk Standard Time, 001): null,
+  (North Korea Standard Time, 001): [
+    Asia/Pyongyang
+  ],
+  (Omsk Standard Time, 001): [
+    Asia/Omsk
+  ],
   (Pacific SA Standard Time, 001): [
     Santiago
   ],
@@ -279,7 +387,9 @@
   (Paraguay Standard Time, 001): [
     Asuncion
   ],
-  (Qyzylorda Standard Time, 001): null,
+  (Qyzylorda Standard Time, 001): [
+    Asia/Qyzylorda
+  ],
   (Romance Standard Time, 001): [
     Paris
   ],
@@ -308,7 +418,18 @@
     Moscow,
     St. Petersburg
   ],
-  (SA Eastern Standard Time, 001): null,
+  (SA Eastern Standard Time, 001): [
+    America/Cayenne
+  ],
+  (SA Eastern Standard Time, BR): [
+    America/Fortaleza
+  ],
+  (SA Eastern Standard Time, FK): [
+    Atlantic/Stanley
+  ],
+  (SA Eastern Standard Time, SR): [
+    America/Paramaribo
+  ],
   (SA Pacific Standard Time, 001): [
     Bogota
   ],
@@ -389,13 +510,21 @@
   (SE Asia Standard Time, ID): [
     Jakarta
   ],
-  (Saint Pierre Standard Time, 001): null,
-  (Sakhalin Standard Time, 001): null,
+  (Saint Pierre Standard Time, 001): [
+    America/Miquelon
+  ],
+  (Sakhalin Standard Time, 001): [
+    Asia/Sakhalin
+  ],
   (Samoa Standard Time, 001): [
     Samoa
   ],
-  (Sao Tome Standard Time, 001): null,
-  (Saratov Standard Time, 001): null,
+  (Sao Tome Standard Time, 001): [
+    Africa/Sao_Tome
+  ],
+  (Saratov Standard Time, 001): [
+    Europe/Saratov
+  ],
   (Singapore Standard Time, 001): [
     Singapore
   ],
@@ -423,48 +552,116 @@
   (South Africa Standard Time, ZW): [
     Harare
   ],
-  (South Sudan Standard Time, 001): null,
+  (South Sudan Standard Time, 001): [
+    Africa/Juba
+  ],
   (Sri Lanka Standard Time, 001): [
     Sri Jayawardenepura
   ],
-  (Sudan Standard Time, 001): null,
-  (Syria Standard Time, 001): null,
+  (Sudan Standard Time, 001): [
+    Africa/Khartoum
+  ],
+  (Syria Standard Time, 001): [
+    Asia/Damascus
+  ],
   (Taipei Standard Time, 001): [
     Taipei
   ],
   (Tasmania Standard Time, 001): [
     Hobart
   ],
-  (Tocantins Standard Time, 001): null,
+  (Tocantins Standard Time, 001): [
+    America/Araguaina
+  ],
   (Tokyo Standard Time, 001): [
     Osaka,
     Sapporo,
     Tokyo
   ],
-  (Tomsk Standard Time, 001): null,
+  (Tomsk Standard Time, 001): [
+    Asia/Tomsk
+  ],
   (Tonga Standard Time, 001): [
     Nuku'alofa
   ],
-  (Transbaikal Standard Time, 001): null,
+  (Transbaikal Standard Time, 001): [
+    Asia/Chita
+  ],
   (Turkey Standard Time, 001): [
     Istanbul
   ],
-  (Turks And Caicos Standard Time, 001): null,
+  (Turks And Caicos Standard Time, 001): [
+    America/Grand_Turk
+  ],
   (US Eastern Standard Time, 001): [
     Indiana (East)
   ],
   (US Mountain Standard Time, 001): [
     Arizona
   ],
-  (UTC+12, 001): null,
-  (UTC+13, 001): null,
+  (UTC+12, 001): [
+    +12:00
+  ],
+  (UTC+12, KI): [
+    Marshall Is.
+  ],
+  (UTC+12, MH): [
+    Marshall Is.
+  ],
+  (UTC+12, NR): [
+    Pacific/Nauru
+  ],
+  (UTC+12, TV): [
+    Pacific/Funafuti
+  ],
+  (UTC+12, UM): [
+    Marshall Is.
+  ],
+  (UTC+12, WF): [
+    Marshall Is.
+  ],
+  (UTC+13, 001): [
+    +13:00
+  ],
+  (UTC+13, KI): [
+    Pacific/Kanton
+  ],
+  (UTC+13, TK): [
+    Tokelau Is.
+  ],
   (UTC, 001): [
     UTC
   ],
-  (UTC-02, 001): null,
-  (UTC-08, 001): null,
-  (UTC-09, 001): null,
-  (UTC-11, 001): null,
+  (UTC-02, 001): [
+    Etc/GMT+2
+  ],
+  (UTC-02, BR): [
+    America/Noronha
+  ],
+  (UTC-08, 001): [
+    Etc/GMT+8
+  ],
+  (UTC-08, PN): [
+    Pacific/Pitcairn
+  ],
+  (UTC-09, 001): [
+    Etc/GMT+9
+  ],
+  (UTC-09, PF): [
+    Pacific/Gambier
+  ],
+  (UTC-11, 001): [
+    -11:00
+  ],
+  (UTC-11, AS): [
+    American Samoa
+  ],
+  (UTC-11, NU): [
+    Pacific/Niue
+  ],
+  (UTC-11, UM): [
+    Midway Island
+  ],
   (Ulaanbaatar Standard Time, 001): [
     Ulaanbaatar
   ],
@@ -480,7 +677,45 @@
   (W. Australia Standard Time, 001): [
     Perth
   ],
-  (W. Central Africa Standard Time, 001): null,
+  (W. Central Africa Standard Time, 001): [
+    Africa/Lagos
+  ],
+  (W. Central Africa Standard Time, AO): [
+    Africa/Luanda
+  ],
+  (W. Central Africa Standard Time, BJ): [
+    Africa/Porto-Novo
+  ],
+  (W. Central Africa Standard Time, CD): [
+    Africa/Kinshasa
+  ],
+  (W. Central Africa Standard Time, CF): [
+    Africa/Bangui
+  ],
+  (W. Central Africa Standard Time, CG): [
+    Africa/Brazzaville
+  ],
+  (W. Central Africa Standard Time, CM): [
+    Africa/Douala
+  ],
+  (W. Central Africa Standard Time, DZ): [
+    West Central Africa
+  ],
+  (W. Central Africa Standard Time, GA): [
+    Africa/Libreville
+  ],
+  (W. Central Africa Standard Time, GQ): [
+    Africa/Malabo
+  ],
+  (W. Central Africa Standard Time, NE): [
+    Africa/Niamey
+  ],
+  (W. Central Africa Standard Time, TD): [
+    Africa/Ndjamena
+  ],
+  (W. Central Africa Standard Time, TN): [
+    Africa/Tunis
+  ],
   (W. Europe Standard Time, 001): [
     Berlin
   ],
@@ -516,7 +751,9 @@
   (W. Europe Standard Time, VA): [
     Rome
   ],
-  (W. Mongolia Standard Time, 001): null,
+  (W. Mongolia Standard Time, 001): [
+    Asia/Hovd
+  ],
   (West Asia Standard Time, 001): [
     Tashkent
   ],
@@ -524,7 +761,9 @@
     Almaty,
     Astana
   ],
-  (West Bank Standard Time, 001): null,
+  (West Bank Standard Time, 001): [
+    Asia/Hebron
+  ],
   (West Pacific Standard Time, 001): [
     Port Moresby
   ],
@@ -538,6 +777,6 @@
     Yakutsk
   ],
   (Yukon Standard Time, 001): [
-    Arizona
+    America/Whitehorse
   ]
 }
\ No newline at end of file
diff --git a/test/TimeZoneConverter.Tests/IanaToRailsTests.cs b/test/TimeZoneConverter.Tests/IanaToRailsTests.cs
index be10631..f210510 100644
--- a/test/TimeZoneConverter.Tests/IanaToRailsTests.cs
+++ b/test/TimeZoneConverter.Tests/IanaToRailsTests.cs
@@ -53,6 +53,7 @@ public IanaToRailsTests(ITestOutputHelper output)
         "America/Coyhaique",
         "America/Cuiaba",
         "America/Danmarkshavn",
+        "America/Dawson",
         "America/Fortaleza",
         "America/Grand_Turk",
         "America/Havana",
@@ -64,6 +65,7 @@ public IanaToRailsTests(ITestOutputHelper output)
         "America/Punta_Arenas",
         "America/Recife",
         "America/Santarem",
+        "America/Whitehorse",
         "Antarctica/Palmer",
         "Antarctica/Rothera",
         "Antarctica/Troll",
@@ -89,6 +91,7 @@ public IanaToRailsTests(ITestOutputHelper output)
         "Australia/LHI",
         "Australia/Lord_Howe",
         "Brazil/DeNoronha",
+        "Canada/Yukon",
         "Chile/EasterIsland",
         "Cuba",
         "Etc/GMT-1",