From 7aa72892312b90c44082700552f569fe9c7964b1 Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Thu, 31 Aug 2023 17:47:53 +0200
Subject: [PATCH 01/14] Initial changed for timezone hybrid mode

---
 .../src/Interop/Interop.TimeZoneInfo.iOS.cs   | 21 +++++
 .../System.Private.CoreLib.Shared.projitems   | 14 ++--
 ...TimeZoneInfo.FullGlobalizationData.Unix.cs | 50 +++++++++---
 .../TimeZoneInfo.FullGlobalizationData.cs     | 10 +++
 .../TimeZoneInfo.MinimalGlobalizationData.cs  | 47 -----------
 .../src/System/TimeZoneInfo.Unix.cs           | 17 +++-
 .../System.Runtime/System.Runtime.sln         |  2 +
 .../Hybrid/System.Runtime.IOS.Tests.csproj    | 22 +++++
 .../tests/System/TimeZoneInfoTests.cs         |  9 ++-
 src/mono/mono/mini/CMakeLists.txt             |  3 +-
 .../CMakeLists.txt                            |  3 +-
 .../System.Globalization.Native/entrypoints.c |  1 +
 .../pal_timeZoneInfo.h                        |  5 ++
 .../pal_timeZoneInfo.m                        | 80 +++++++++++++++++++
 14 files changed, 212 insertions(+), 72 deletions(-)
 create mode 100644 src/libraries/Common/src/Interop/Interop.TimeZoneInfo.iOS.cs
 delete mode 100644 src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs
 create mode 100644 src/libraries/System.Runtime/tests/Hybrid/System.Runtime.IOS.Tests.csproj
 create mode 100644 src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m

diff --git a/src/libraries/Common/src/Interop/Interop.TimeZoneInfo.iOS.cs b/src/libraries/Common/src/Interop/Interop.TimeZoneInfo.iOS.cs
new file mode 100644
index 00000000000000..9575fc3dc3359c
--- /dev/null
+++ b/src/libraries/Common/src/Interop/Interop.TimeZoneInfo.iOS.cs
@@ -0,0 +1,21 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class Globalization
+    {
+        [LibraryImport(Libraries.GlobalizationNative, EntryPoint = "GlobalizationNative_GetTimeZoneDisplayNameNative", StringMarshalling = StringMarshalling.Utf16)]
+        internal static unsafe partial ResultCode GetTimeZoneDisplayNameNative(
+            string localeName,
+            int lNameLength,
+            string timeZoneId,
+            int idLength,
+            TimeZoneDisplayNameType type,
+            char* result,
+            int resultLength);
+    }
+}
diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index 14b8a814732670..2697c28b020f30 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -1272,7 +1272,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZone.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.AdjustmentRule.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.cs" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.cs" Condition="'$(UseMinimalGlobalizationData)' != 'true'" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.StringSerializer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.TransitionTime.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneNotFoundException.cs" />
@@ -1357,12 +1357,15 @@
     <Compile Include="$(CommonPath)Interop\Interop.ResultCode.cs">
       <Link>Common\Interop\Interop.ResultCode.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneDisplayNameType.cs" Condition="'$(UseMinimalGlobalizationData)' != 'true'">
+    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneDisplayNameType.cs">
       <Link>Common\Interop\Interop.TimeZoneDisplayNameType.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneInfo.cs" Condition="'$(UseMinimalGlobalizationData)' != 'true'">
+    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneInfo.cs">
       <Link>Common\Interop\Interop.TimeZoneInfo.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneInfo.iOS.cs" Condition="'$(IsiOSLike)' == 'true'">
+      <Link>Common\Interop\Interop.TimeZoneInfo.iOS.cs</Link>
+    </Compile>
     <Compile Include="$(CommonPath)Interop\Interop.Utils.cs">
       <Link>Common\Interop\Interop.Utils.cs</Link>
     </Compile>
@@ -2500,7 +2503,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.iOS.cs" Condition="'$(IsiOSLike)' == 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.OSVersion.Unix.cs" Condition="'$(IsOSXLike)' != 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.SunOS.cs" Condition="'$(Targetsillumos)' == 'true' or '$(TargetsSolaris)' == 'true'" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.Unix.cs" Condition="'$(UseMinimalGlobalizationData)' != 'true'" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\DriveInfoInternal.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\PersistedFiles.Unix.cs" />
   </ItemGroup>
@@ -2516,9 +2519,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\PersistedFiles.Browser.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\InteropServices\RuntimeInformation.Browser.cs" />
   </ItemGroup>
-  <ItemGroup Condition="'$(UseMinimalGlobalizationData)' == 'true'">
-    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.MinimalGlobalizationData.cs" />
-  </ItemGroup>
   <ItemGroup Condition="'$(IsOSXLike)' == 'true'">
     <Compile Include="$(CommonPath)Interop\OSX\Interop.libobjc.cs">
       <Link>Common\Interop\OSX\Interop.libobjc.cs</Link>
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index c10fdfb54be855..d76458f8373220 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -28,6 +28,14 @@ public sealed partial class TimeZoneInfo
         // Helper function to get the standard display name for the UTC static time zone instance
         private static string GetUtcStandardDisplayName()
         {
+            System.Diagnostics.Debug.Write("TimeZoneInfo.GetUtcStandardDisplayName is called.\n");
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+            if (!GlobalizationMode.Hybrid)
+            {
+                // For this target, be consistent with other time zone display names that use an abbreviation.
+                return "UTC";
+            }
+#endif
             // Don't bother looking up the name for invariant or English cultures
             CultureInfo uiCulture = CultureInfo.CurrentUICulture;
             if (GlobalizationMode.Invariant || uiCulture.Name.Length == 0 || uiCulture.TwoLetterISOLanguageName == "en")
@@ -48,6 +56,13 @@ private static string GetUtcStandardDisplayName()
         // Helper function to get the full display name for the UTC static time zone instance
         private static string GetUtcFullDisplayName(string timeZoneId, string standardDisplayName)
         {
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+            if (!GlobalizationMode.Hybrid)
+            {
+                // For this target, be consistent with other time zone display names that use the ID.
+                return $"(UTC) {timeZoneId}";
+            }
+#endif
             return $"(UTC) {standardDisplayName}";
         }
 #pragma warning restore IDE0060
@@ -89,19 +104,24 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                 return;
             }
 
-            string? timeZoneDisplayName;
-            bool result = Interop.CallStringMethod(
-                (buffer, locale, id, type) =>
+        string? timeZoneDisplayName;
+        bool result = Interop.CallStringMethod(
+            (buffer, locale, id, type) =>
+            {
+                fixed (char* bufferPtr = buffer)
                 {
-                    fixed (char* bufferPtr = buffer)
-                    {
-                        return Interop.Globalization.GetTimeZoneDisplayName(locale, id, type, bufferPtr, buffer.Length);
-                    }
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+                    if (GlobalizationMode.Hybrid)
+                        return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
+#endif
+                    return Interop.Globalization.GetTimeZoneDisplayName(locale, id, type, bufferPtr, buffer.Length);
+                }
                 },
                 uiCulture,
                 timeZoneId,
                 nameType,
                 out timeZoneDisplayName);
+System.Diagnostics.Debug.Write("After First call TimeZoneInfo.GetDisplayName: timeZoneDisplayName = " + timeZoneDisplayName + "\n");
 
             if (!result && uiCulture != FallbackCultureName)
             {
@@ -111,6 +131,10 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                     {
                         fixed (char* bufferPtr = buffer)
                         {
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+                            if (GlobalizationMode.Hybrid)
+                                return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
+#endif
                             return Interop.Globalization.GetTimeZoneDisplayName(locale, id, type, bufferPtr, buffer.Length);
                         }
                     },
@@ -119,7 +143,6 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                     nameType,
                     out timeZoneDisplayName);
             }
-
             // If there is an unknown error, don't set the displayName field.
             // It will be set to the abbreviation that was read out of the tzfile.
             if (result && !string.IsNullOrEmpty(timeZoneDisplayName))
@@ -239,7 +262,7 @@ private static void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan
 
         // Helper function that gets an exmplar city name either from ICU or from the IANA time zone ID itself
         private static string GetExemplarCityName(string timeZoneId, string uiCultureName)
-        {
+        {//
             // First try to get the name through the localization data.
             string? exemplarCityName = null;
             GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.ExemplarCity, uiCultureName, ref exemplarCityName);
@@ -256,8 +279,17 @@ private static string GetExemplarCityName(string timeZoneId, string uiCultureNam
         // Helper function that returns an alternative ID using ICU data. Used primarily for converting from Windows IDs.
         private static unsafe string? GetAlternativeId(string id, out bool idIsIana)
         {
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+            //if (!GlobalizationMode.Hybrid)
+            //{
+                // No alternative IDs in this target.
+                idIsIana = false;
+                return null;
+            //}
+#else
             idIsIana = false;
             return TryConvertWindowsIdToIanaId(id, null, out string? ianaId) ? ianaId : null;
+#endif
         }
     }
 }
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
index 17b677ca37a9ae..09b05f15a8cd87 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
@@ -9,6 +9,10 @@ public sealed partial class TimeZoneInfo
     {
         private static unsafe bool TryConvertIanaIdToWindowsId(string ianaId, bool allocate, out string? windowsId)
         {
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS || TARGET_BROWSER
+                windowsId = null;
+                return false;
+#else
             if (GlobalizationMode.Invariant ||
                 GlobalizationMode.UseNls ||
                 ianaId is null ||
@@ -28,10 +32,15 @@ ianaId is null ||
 
             windowsId = null;
             return false;
+#endif
         }
 
         private static unsafe bool TryConvertWindowsIdToIanaId(string windowsId, string? region, bool allocate,  out string? ianaId)
         {
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS || TARGET_BROWSER
+                ianaId = null;
+                return false;
+#else
             // This functionality is not enabled in the browser for the sake of size reduction.
             if (GlobalizationMode.Invariant || GlobalizationMode.UseNls || windowsId is null)
             {
@@ -88,6 +97,7 @@ private static unsafe bool TryConvertWindowsIdToIanaId(string windowsId, string?
 
             ianaId = null;
             return false;
+#endif
         }
 
     }
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs
deleted file mode 100644
index fa1d25e4933352..00000000000000
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs
+++ /dev/null
@@ -1,47 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-namespace System
-{
-    public sealed partial class TimeZoneInfo
-    {
-#pragma warning disable IDE0060
-        static partial void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan baseUtcOffset, ref string? displayName);
-
-        static partial void GetStandardDisplayName(string timeZoneId, ref string? displayName);
-
-        static partial void GetDaylightDisplayName(string timeZoneId, ref string? displayName);
-
-        private static string GetUtcStandardDisplayName()
-        {
-            // For this target, be consistent with other time zone display names that use an abbreviation.
-            return "UTC";
-        }
-
-        private static string GetUtcFullDisplayName(string timeZoneId, string standardDisplayName)
-        {
-            // For this target, be consistent with other time zone display names that use the ID.
-            return $"(UTC) {timeZoneId}";
-        }
-
-        private static string? GetAlternativeId(string id, out bool idIsIana)
-        {
-            // No alternative IDs in this target.
-            idIsIana = false;
-            return null;
-        }
-
-        private static unsafe bool TryConvertIanaIdToWindowsId(string ianaId, bool allocate, out string? windowsId)
-        {
-            windowsId = null;
-            return false;
-        }
-
-        private static unsafe bool TryConvertWindowsIdToIanaId(string windowsId, string? region, bool allocate,  out string? ianaId)
-        {
-            ianaId = null;
-            return false;
-        }
-#pragma warning restore IDE0060
-    }
-}
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
index 2524b4fd536066..a6157e256c6667 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
@@ -231,9 +231,14 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return displayName;
 
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS || TARGET_BROWSER
+            return displayName;
+            // if (GlobalizationMode.Hybrid)
+            //     GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
+#else
             GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
-
             return displayName;
+#endif
         }
 
         private string? PopulateStandardDisplayName()
@@ -245,8 +250,11 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return standardDisplayName;
 
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS || TARGET_BROWSER
+            if (!GlobalizationMode.Hybrid)
+                return standardDisplayName;
+#endif
             GetStandardDisplayName(Id, ref standardDisplayName);
-
             return standardDisplayName;
         }
 
@@ -259,8 +267,11 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return daylightDisplayName;
 
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+            if (!GlobalizationMode.Hybrid)
+                return daylightDisplayName;
+#endif
             GetDaylightDisplayName(Id, ref daylightDisplayName);
-
             return daylightDisplayName;
         }
 
diff --git a/src/libraries/System.Runtime/System.Runtime.sln b/src/libraries/System.Runtime/System.Runtime.sln
index a7d50d4a347abd..4ef7e0094581f3 100644
--- a/src/libraries/System.Runtime/System.Runtime.sln
+++ b/src/libraries/System.Runtime/System.Runtime.sln
@@ -27,6 +27,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.Nls.Tests",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.Tests", "tests\System.Runtime.Tests.csproj", "{4EE36055-AD7C-4779-B3F6-08687960DCC3}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.IOS.Tests", "tests\Hybrid\System.Runtime.IOS.Tests.csproj", "{4EE36055-AD7C-4779-B3F6-08687960DCC3}"
+EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.ReflectionInvokeEmit.Tests", "tests\System\Reflection\InvokeEmit\System.Runtime.ReflectionInvokeEmit.Tests.csproj", "{C3F25EEF-04B4-407A-960B-0C1CE9C04430}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.ReflectionInvokeInterpreted.Tests", "tests\System\Reflection\InvokeInterpreted\System.Runtime.ReflectionInvokeInterpreted.Tests.csproj", "{47E26787-7C27-4572-AD8B-868DE44E2C48}"
diff --git a/src/libraries/System.Runtime/tests/Hybrid/System.Runtime.IOS.Tests.csproj b/src/libraries/System.Runtime/tests/Hybrid/System.Runtime.IOS.Tests.csproj
new file mode 100644
index 00000000000000..7ab499979f3928
--- /dev/null
+++ b/src/libraries/System.Runtime/tests/Hybrid/System.Runtime.IOS.Tests.csproj
@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>$(NetCoreAppCurrent)-ios;$(NetCoreAppCurrent)-tvos;$(NetCoreAppCurrent)-maccatalyst</TargetFrameworks>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <TestRuntime>true</TestRuntime>
+    <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
+    <HybridGlobalization>true</HybridGlobalization>
+  </PropertyGroup>
+
+  <!--
+    Add special trait for running local timezone validation tests on certain devices e.g. in CI to make sure the local timezone is correct and not UTC. Disable these tests otherwise.
+  -->
+  <PropertyGroup>
+    <WithoutCategories Condition="'$(EnableAdditionalTimezoneChecks)' != 'true'">$(WithoutCategories);AdditionalTimezoneChecks</WithoutCategories>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="..\System\TimeZoneInfoTests.cs" />
+    <Compile Include="..\System\TimeZoneTests.cs" />
+    <Compile Include="..\System\TimeZoneNotFoundExceptionTests.cs" />
+  </ItemGroup>
+</Project>
diff --git a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
index 7efe9c0cde1dcf..d0e98f58afee03 100644
--- a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
+++ b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
@@ -89,7 +89,7 @@ public static void Names()
         //  Name abbreviations, if available, are used instead
         public static IEnumerable<object[]> Platform_TimeZoneNamesTestData()
         {
-            if (PlatformDetection.IsBrowser || PlatformDetection.IsiOS || PlatformDetection.IstvOS)
+            if (PlatformDetection.IsBrowser || (!PlatformDetection.IsHybridGlobalizationOnOSX  && (PlatformDetection.IsiOS || PlatformDetection.IstvOS)))
                 return new TheoryData<TimeZoneInfo, string, string, string, string>
                 {
                     { TimeZoneInfo.FindSystemTimeZoneById(s_strPacific), "(UTC-08:00) America/Los_Angeles", null, "PST", "PDT" },
@@ -137,9 +137,10 @@ public static void Platform_TimeZoneNames(TimeZoneInfo tzi, string displayName,
                     displayName = displayName.Replace(c.ToString(), "", StringComparison.Ordinal);
                 }
             }
+            System.Diagnostics.Debug.Write("Platform_TimeZoneNames: Display Name: " + tzi.DisplayName + "\n"+ alternativeDisplayName + "\n" + displayName + "\n" + standardName + "\n" + daylightName + "\n");
 
-            Assert.True(displayName == tzi.DisplayName || alternativeDisplayName == tzi.DisplayName,
-                         $"Display Name: Neither '{displayName}' nor '{alternativeDisplayName}' equal to '{tzi.DisplayName}'");
+            // Assert.True(displayName == tzi.DisplayName || alternativeDisplayName == tzi.DisplayName,
+            //              $"Display Name: Neither '{displayName}' nor '{alternativeDisplayName}' equal to '{tzi.DisplayName}'");
             Assert.Equal(standardName, tzi.StandardName);
             Assert.Equal(daylightName, tzi.DaylightName);
         }
@@ -2802,7 +2803,7 @@ public static void TimeZoneInfo_DisplayNameStartsWithOffset(TimeZoneInfo tzi)
                 if (PlatformDetection.IsNotWindowsNanoServer && !PlatformDetection.IsWindows7)
                 {
                     string offset = (match.Groups["sign"].Value == "-" ? "-" : "") + match.Groups["amount"].Value;
-                    TimeSpan ts = TimeSpan.Parse(offset);
+                    TimeSpan ts = TimeSpan.Parse(offset);// this throws exception
                     if (PlatformDetection.IsWindows &&
                         tzi.BaseUtcOffset != ts &&
                         (tzi.Id.Contains("Morocco") || tzi.Id.Contains("Volgograd")))
diff --git a/src/mono/mono/mini/CMakeLists.txt b/src/mono/mono/mini/CMakeLists.txt
index 6b300ab2b74cfa..01a0cd68e8d3ef 100644
--- a/src/mono/mono/mini/CMakeLists.txt
+++ b/src/mono/mono/mini/CMakeLists.txt
@@ -75,7 +75,8 @@ if(HAVE_SYS_ICU)
         pal_collation.m
         pal_casing.m
         pal_calendarData.m
-        pal_normalization.m)
+        pal_normalization.m
+        pal_timeZoneInfo.m)
 
     addprefix(icu_shim_darwin_sources "${ICU_SHIM_PATH}" "${icu_shim_darwin_sources_base}")
     set(icu_shim_sources ${icu_shim_sources} ${icu_shim_darwin_sources})
diff --git a/src/native/libs/System.Globalization.Native/CMakeLists.txt b/src/native/libs/System.Globalization.Native/CMakeLists.txt
index d6dfcb65bf3284..d218c968eb04b4 100644
--- a/src/native/libs/System.Globalization.Native/CMakeLists.txt
+++ b/src/native/libs/System.Globalization.Native/CMakeLists.txt
@@ -98,7 +98,8 @@ if (CLR_CMAKE_TARGET_APPLE)
         pal_collation.m
         pal_casing.m
         pal_calendarData.m
-        pal_normalization.m)
+        pal_normalization.m
+        pal_timeZoneInfo.m)
     set_source_files_properties(${NATIVEGLOBALIZATION_SOURCES_OBJC} PROPERTIES COMPILE_FLAGS "-fobjc-arc ${CLR_CMAKE_COMMON_OBJC_FLAGS}")
     set(NATIVEGLOBALIZATION_SOURCES ${NATIVEGLOBALIZATION_SOURCES} ${NATIVEGLOBALIZATION_SOURCES_OBJC})
 endif()
diff --git a/src/native/libs/System.Globalization.Native/entrypoints.c b/src/native/libs/System.Globalization.Native/entrypoints.c
index 11ab93883cb0d9..799b15ed2ca760 100644
--- a/src/native/libs/System.Globalization.Native/entrypoints.c
+++ b/src/native/libs/System.Globalization.Native/entrypoints.c
@@ -70,6 +70,7 @@ static const Entry s_globalizationNative[] =
     DllImportEntry(GlobalizationNative_GetLocaleInfoStringNative)
     DllImportEntry(GlobalizationNative_GetLocaleNameNative)
     DllImportEntry(GlobalizationNative_GetLocaleTimeFormatNative)
+    DllImportEntry(GlobalizationNative_GetTimeZoneDisplayNameNative)
     DllImportEntry(GlobalizationNative_IndexOfNative)
     DllImportEntry(GlobalizationNative_IsNormalizedNative)
     DllImportEntry(GlobalizationNative_NormalizeStringNative)
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
index b91469e6a1341a..9e57b12dc2cbe7 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
@@ -23,3 +23,8 @@ typedef enum
 PALEXPORT int32_t GlobalizationNative_WindowsIdToIanaId(const UChar* windowsId, const char* region, UChar* ianaId, int32_t ianaIdLength);
 PALEXPORT int32_t GlobalizationNative_IanaIdToWindowsId(const UChar* ianaId, UChar* windowsId, int32_t windowsIdLength);
 PALEXPORT ResultCode GlobalizationNative_GetTimeZoneDisplayName(const UChar* localeName, const UChar* timeZoneId, TimeZoneDisplayNameType type, UChar* result, int32_t resultLength);
+
+#ifdef __APPLE__
+PALEXPORT int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeName, int32_t lNameLength, const uint16_t* timeZoneId, int32_t timeZoneIdLength,
+                                                                TimeZoneDisplayNameType type, uint16_t* result, int32_t resultLength);
+#endif
\ No newline at end of file
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
new file mode 100644
index 00000000000000..71db157f98803c
--- /dev/null
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
@@ -0,0 +1,80 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+//
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "pal_errors_internal.h"
+#include "pal_locale_internal.h"
+#include "pal_timeZoneInfo.h"
+
+#import <Foundation/Foundation.h>
+#if defined(TARGET_MACCATALYST) || defined(TARGET_IOS) || defined(TARGET_TVOS)
+
+/*
+Gets the localized display name that is currently in effect for the specified time zone.
+*/
+int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeName, int32_t lNameLength, const uint16_t* timeZoneId, int32_t timeZoneIdLength,
+                                                      TimeZoneDisplayNameType type, uint16_t* result, int32_t resultLength)
+{
+    @autoreleasepool
+    {
+        NSLocale *currentLocale;
+        if(localeName == NULL || lNameLength == 0)
+        {
+            currentLocale = [NSLocale systemLocale];
+        }
+        else
+        {
+            NSString *locName = [NSString stringWithCharacters: localeName length: lNameLength];
+            currentLocale = [NSLocale localeWithLocaleIdentifier:locName];
+        }
+         //NSTimeZone* timeZone = [NSTimeZone localTimeZone];
+        NSString* tzName = [NSString stringWithCharacters: timeZoneId length: timeZoneIdLength];
+        NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:tzName];
+        NSTimeZoneNameStyle style;
+
+        switch (type)
+        {
+            case TimeZoneDisplayName_Standard:
+                style = NSTimeZoneNameStyleStandard;//;NSTimeZoneNameStyleShortStandard
+                break;
+            case TimeZoneDisplayName_DaylightSavings:
+                style = NSTimeZoneNameStyleDaylightSaving;//;NSTimeZoneNameStyleShortDaylightSaving
+                break;
+            case TimeZoneDisplayName_Generic:
+                style = NSTimeZoneNameStyleGeneric;//;NSTimeZoneNameStyleShortGeneric
+                break;
+            // case TimeZoneDisplayName_GenericLocation:
+            //     style = NSTimeZoneNameStyleStandard;//???
+            //     break;
+            // case TimeZoneDisplayName_ExemplarCity:
+            //     style = NSTimeZoneNameStyleStandard;//??
+            //     break;
+            default:
+                return UnknownError;//-1;
+        }
+
+        NSString* timeZoneName = [timeZone localizedName:style locale:currentLocale];
+        if (timeZoneName == NULL || timeZoneName.length == 0)
+        {
+            return UnknownError;//0
+        }
+
+        int32_t index = 0, dstIdx = 0, isError = 0;
+        uint16_t dstCodepoint;
+        while (index < timeZoneName.length)
+        {
+            dstCodepoint = [timeZoneName characterAtIndex: index];
+            Append(result, dstIdx, resultLength, dstCodepoint, isError);
+            index++;
+        }
+        dstCodepoint = '\0';
+        Append(result, dstIdx, resultLength, dstCodepoint, isError);
+
+        return isError ? UnknownError : Success;//timeZoneName.length;//;
+    }
+}
+#endif

From cfd0f5ba6e910676cef53b0f867029fabf9add7d Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Fri, 1 Sep 2023 12:03:21 +0200
Subject: [PATCH 02/14] Refactoring

---
 ...TimeZoneInfo.FullGlobalizationData.Unix.cs | 57 ++++++++++---------
 .../TimeZoneInfo.FullGlobalizationData.cs     |  8 +--
 .../src/System/TimeZoneInfo.Unix.cs           |  9 ++-
 .../Hybrid/System.Runtime.IOS.Tests.csproj    |  3 -
 .../tests/System/TimeZoneInfoTests.cs         |  7 +--
 .../pal_timeZoneInfo.h                        |  4 +-
 .../pal_timeZoneInfo.m                        |  1 -
 7 files changed, 43 insertions(+), 46 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index d76458f8373220..72d1e8195ac27d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -29,7 +29,10 @@ public sealed partial class TimeZoneInfo
         private static string GetUtcStandardDisplayName()
         {
             System.Diagnostics.Debug.Write("TimeZoneInfo.GetUtcStandardDisplayName is called.\n");
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+#if TARGET_BROWSER || TARGET_WASI
+            // For this target, be consistent with other time zone display names that use an abbreviation.
+            return "UTC";
+#elif TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
             {
                 // For this target, be consistent with other time zone display names that use an abbreviation.
@@ -56,7 +59,10 @@ private static string GetUtcStandardDisplayName()
         // Helper function to get the full display name for the UTC static time zone instance
         private static string GetUtcFullDisplayName(string timeZoneId, string standardDisplayName)
         {
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+#if TARGET_BROWSER || TARGET_WASI
+            // For this target, be consistent with other time zone display names that use the ID.
+            return $"(UTC) {timeZoneId}";
+#elif TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
             {
                 // For this target, be consistent with other time zone display names that use the ID.
@@ -104,24 +110,23 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                 return;
             }
 
-        string? timeZoneDisplayName;
-        bool result = Interop.CallStringMethod(
-            (buffer, locale, id, type) =>
-            {
-                fixed (char* bufferPtr = buffer)
+            string? timeZoneDisplayName;
+            bool result = Interop.CallStringMethod(
+                (buffer, locale, id, type) =>
                 {
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
-                    if (GlobalizationMode.Hybrid)
-                        return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
+                    fixed (char* bufferPtr = buffer)
+                    {
+#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+                        if (GlobalizationMode.Hybrid)
+                            return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
 #endif
-                    return Interop.Globalization.GetTimeZoneDisplayName(locale, id, type, bufferPtr, buffer.Length);
-                }
-                },
-                uiCulture,
-                timeZoneId,
-                nameType,
-                out timeZoneDisplayName);
-System.Diagnostics.Debug.Write("After First call TimeZoneInfo.GetDisplayName: timeZoneDisplayName = " + timeZoneDisplayName + "\n");
+                        return Interop.Globalization.GetTimeZoneDisplayName(locale, id, type, bufferPtr, buffer.Length);
+                    }
+                    },
+                    uiCulture,
+                    timeZoneId,
+                    nameType,
+                    out timeZoneDisplayName);
 
             if (!result && uiCulture != FallbackCultureName)
             {
@@ -131,7 +136,7 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                     {
                         fixed (char* bufferPtr = buffer)
                         {
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
                             if (GlobalizationMode.Hybrid)
                                 return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
 #endif
@@ -143,6 +148,7 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                     nameType,
                     out timeZoneDisplayName);
             }
+
             // If there is an unknown error, don't set the displayName field.
             // It will be set to the abbreviation that was read out of the tzfile.
             if (result && !string.IsNullOrEmpty(timeZoneDisplayName))
@@ -262,7 +268,7 @@ private static void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan
 
         // Helper function that gets an exmplar city name either from ICU or from the IANA time zone ID itself
         private static string GetExemplarCityName(string timeZoneId, string uiCultureName)
-        {//
+        {
             // First try to get the name through the localization data.
             string? exemplarCityName = null;
             GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.ExemplarCity, uiCultureName, ref exemplarCityName);
@@ -279,13 +285,10 @@ private static string GetExemplarCityName(string timeZoneId, string uiCultureNam
         // Helper function that returns an alternative ID using ICU data. Used primarily for converting from Windows IDs.
         private static unsafe string? GetAlternativeId(string id, out bool idIsIana)
         {
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
-            //if (!GlobalizationMode.Hybrid)
-            //{
-                // No alternative IDs in this target.
-                idIsIana = false;
-                return null;
-            //}
+#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+            // No alternative IDs in this target.
+            idIsIana = false;
+            return null;
 #else
             idIsIana = false;
             return TryConvertWindowsIdToIanaId(id, null, out string? ianaId) ? ianaId : null;
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
index 09b05f15a8cd87..6c2e3a962526ec 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
@@ -9,7 +9,7 @@ public sealed partial class TimeZoneInfo
     {
         private static unsafe bool TryConvertIanaIdToWindowsId(string ianaId, bool allocate, out string? windowsId)
         {
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS || TARGET_BROWSER
+#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
                 windowsId = null;
                 return false;
 #else
@@ -37,9 +37,9 @@ ianaId is null ||
 
         private static unsafe bool TryConvertWindowsIdToIanaId(string windowsId, string? region, bool allocate,  out string? ianaId)
         {
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS || TARGET_BROWSER
-                ianaId = null;
-                return false;
+#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+            ianaId = null;
+            return false;
 #else
             // This functionality is not enabled in the browser for the sake of size reduction.
             if (GlobalizationMode.Invariant || GlobalizationMode.UseNls || windowsId is null)
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
index a6157e256c6667..e5a36bee754e9b 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
@@ -231,10 +231,8 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return displayName;
 
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS || TARGET_BROWSER
+#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER  || TARGET_WASI
             return displayName;
-            // if (GlobalizationMode.Hybrid)
-            //     GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
 #else
             GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
             return displayName;
@@ -250,11 +248,12 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return standardDisplayName;
 
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS || TARGET_BROWSER
+#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
             if (!GlobalizationMode.Hybrid)
                 return standardDisplayName;
 #endif
             GetStandardDisplayName(Id, ref standardDisplayName);
+
             return standardDisplayName;
         }
 
@@ -267,7 +266,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return daylightDisplayName;
 
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
             if (!GlobalizationMode.Hybrid)
                 return daylightDisplayName;
 #endif
diff --git a/src/libraries/System.Runtime/tests/Hybrid/System.Runtime.IOS.Tests.csproj b/src/libraries/System.Runtime/tests/Hybrid/System.Runtime.IOS.Tests.csproj
index 7ab499979f3928..ca2e3b7856cda5 100644
--- a/src/libraries/System.Runtime/tests/Hybrid/System.Runtime.IOS.Tests.csproj
+++ b/src/libraries/System.Runtime/tests/Hybrid/System.Runtime.IOS.Tests.csproj
@@ -7,9 +7,6 @@
     <HybridGlobalization>true</HybridGlobalization>
   </PropertyGroup>
 
-  <!--
-    Add special trait for running local timezone validation tests on certain devices e.g. in CI to make sure the local timezone is correct and not UTC. Disable these tests otherwise.
-  -->
   <PropertyGroup>
     <WithoutCategories Condition="'$(EnableAdditionalTimezoneChecks)' != 'true'">$(WithoutCategories);AdditionalTimezoneChecks</WithoutCategories>
   </PropertyGroup>
diff --git a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
index d0e98f58afee03..f0caaed62a69a7 100644
--- a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
+++ b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
@@ -137,10 +137,9 @@ public static void Platform_TimeZoneNames(TimeZoneInfo tzi, string displayName,
                     displayName = displayName.Replace(c.ToString(), "", StringComparison.Ordinal);
                 }
             }
-            System.Diagnostics.Debug.Write("Platform_TimeZoneNames: Display Name: " + tzi.DisplayName + "\n"+ alternativeDisplayName + "\n" + displayName + "\n" + standardName + "\n" + daylightName + "\n");
 
-            // Assert.True(displayName == tzi.DisplayName || alternativeDisplayName == tzi.DisplayName,
-            //              $"Display Name: Neither '{displayName}' nor '{alternativeDisplayName}' equal to '{tzi.DisplayName}'");
+            Assert.True(displayName == tzi.DisplayName || alternativeDisplayName == tzi.DisplayName,
+                         $"Display Name: Neither '{displayName}' nor '{alternativeDisplayName}' equal to '{tzi.DisplayName}'");
             Assert.Equal(standardName, tzi.StandardName);
             Assert.Equal(daylightName, tzi.DaylightName);
         }
@@ -2803,7 +2802,7 @@ public static void TimeZoneInfo_DisplayNameStartsWithOffset(TimeZoneInfo tzi)
                 if (PlatformDetection.IsNotWindowsNanoServer && !PlatformDetection.IsWindows7)
                 {
                     string offset = (match.Groups["sign"].Value == "-" ? "-" : "") + match.Groups["amount"].Value;
-                    TimeSpan ts = TimeSpan.Parse(offset);// this throws exception
+                    TimeSpan ts = TimeSpan.Parse(offset);
                     if (PlatformDetection.IsWindows &&
                         tzi.BaseUtcOffset != ts &&
                         (tzi.Id.Contains("Morocco") || tzi.Id.Contains("Volgograd")))
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
index 9e57b12dc2cbe7..28a00e89186a77 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
@@ -26,5 +26,5 @@ PALEXPORT ResultCode GlobalizationNative_GetTimeZoneDisplayName(const UChar* loc
 
 #ifdef __APPLE__
 PALEXPORT int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeName, int32_t lNameLength, const uint16_t* timeZoneId, int32_t timeZoneIdLength,
-                                                                TimeZoneDisplayNameType type, uint16_t* result, int32_t resultLength);
-#endif
\ No newline at end of file
+                                                                   TimeZoneDisplayNameType type, uint16_t* result, int32_t resultLength);
+#endif
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
index 71db157f98803c..b9776af63fb636 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
@@ -31,7 +31,6 @@ int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeN
             NSString *locName = [NSString stringWithCharacters: localeName length: lNameLength];
             currentLocale = [NSLocale localeWithLocaleIdentifier:locName];
         }
-         //NSTimeZone* timeZone = [NSTimeZone localTimeZone];
         NSString* tzName = [NSString stringWithCharacters: timeZoneId length: timeZoneIdLength];
         NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:tzName];
         NSTimeZoneNameStyle style;

From 3678a4869a4e74d0757b9cd26ee62ea458b3f73e Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Fri, 1 Sep 2023 13:27:10 +0200
Subject: [PATCH 03/14] Fix test failure on ios

---
 .../System.Runtime/tests/System/TimeZoneInfoTests.cs   | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
index f0caaed62a69a7..c44010cf2618ca 100644
--- a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
+++ b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
@@ -100,6 +100,16 @@ public static IEnumerable<object[]> Platform_TimeZoneNamesTestData()
                     { s_NewfoundlandTz, "(UTC-03:30) America/St_Johns", null, "NST", "NDT" },
                     { s_catamarcaTz, "(UTC-03:00) America/Argentina/Catamarca", null, "-03", "-02" }
                 };
+            else if(PlatformDetection.IsHybridGlobalizationOnOSX && (PlatformDetection.IsiOS || PlatformDetection.IstvOS))
+                return new TheoryData<TimeZoneInfo, string, string, string, string>
+                {
+                    { TimeZoneInfo.FindSystemTimeZoneById(s_strPacific), "(UTC-08:00) America/Los_Angeles", null, "Pacific Standard Time", "Pacific Daylight Time" },
+                    { TimeZoneInfo.FindSystemTimeZoneById(s_strSydney), "(UTC+10:00) Australia/Sydney", null, "Australian Eastern Standard Time", "Australian Eastern Daylight Time" },
+                    { TimeZoneInfo.FindSystemTimeZoneById(s_strPerth), "(UTC+08:00) Australia/Perth", null, "Australian Western Standard Time", "Australian Western Daylight Time" },
+                    { TimeZoneInfo.FindSystemTimeZoneById(s_strIran), "(UTC+03:30) Asia/Tehran", "(UTC+03:30) Iran Standard Time (Tehran)", "Iran Standard Time", "Iran Daylight Time" },
+                    { s_NewfoundlandTz, "(UTC-03:30) America/St_Johns", null, "Newfoundland Standard Time", "Newfoundland Daylight Time" },
+                    { s_catamarcaTz, "(UTC-03:00) America/Argentina/Catamarca", null, "Argentina Standard Time", "Argentina Summer Time" }
+                };
             else if (PlatformDetection.IsWindows)
                 return new TheoryData<TimeZoneInfo, string, string, string, string>
                 {

From 8cf560993ee6f63a3e85974cbf27587fa5e12568 Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Fri, 1 Sep 2023 14:24:09 +0200
Subject: [PATCH 04/14] Fix wasm build failure

---
 .../src/System.Private.CoreLib.Shared.projitems        |  2 +-
 .../System/TimeZoneInfo.FullGlobalizationData.Unix.cs  | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index 2697c28b020f30..69f337b32600fb 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -2476,6 +2476,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.Android.cs" Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsLinuxBionic)' == 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.NonAndroid.cs" Condition="'$(TargetsAndroid)' != 'true' and '$(TargetsLinuxBionic)' != 'true'" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.Unix.cs" />
   </ItemGroup>
   <ItemGroup Condition="('$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' or '$(TargetsWasi)' == 'true') and '$(IsOSXLike)' != 'true'">
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\FileStatus.SetTimes.OtherUnix.cs" />
@@ -2503,7 +2504,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.iOS.cs" Condition="'$(IsiOSLike)' == 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.OSVersion.Unix.cs" Condition="'$(IsOSXLike)' != 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.SunOS.cs" Condition="'$(Targetsillumos)' == 'true' or '$(TargetsSolaris)' == 'true'" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\DriveInfoInternal.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\PersistedFiles.Unix.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index 72d1e8195ac27d..2660dd8b01ab9c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -122,11 +122,11 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
 #endif
                         return Interop.Globalization.GetTimeZoneDisplayName(locale, id, type, bufferPtr, buffer.Length);
                     }
-                    },
-                    uiCulture,
-                    timeZoneId,
-                    nameType,
-                    out timeZoneDisplayName);
+                },
+                uiCulture,
+                timeZoneId,
+                nameType,
+                out timeZoneDisplayName);
 
             if (!result && uiCulture != FallbackCultureName)
             {

From b44508f68667803fc065e43d99da23b1ff278cce Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Fri, 1 Sep 2023 14:46:09 +0200
Subject: [PATCH 05/14] Fix wasm build

---
 .../System.Private.CoreLib.Shared.projitems   | 14 ++++--
 ...TimeZoneInfo.FullGlobalizationData.Unix.cs | 16 ++-----
 ...imeZoneInfo.MinimalGlobalizationData.cs.cs | 47 +++++++++++++++++++
 .../src/System/TimeZoneInfo.Unix.cs           |  6 +--
 4 files changed, 64 insertions(+), 19 deletions(-)
 create mode 100644 src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs.cs

diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index 69f337b32600fb..2b30fdc91f6bd8 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -20,7 +20,7 @@
     <ILLinkSharedDirectory>$(MSBuildThisFileDirectory)ILLink\</ILLinkSharedDirectory>
     <IsBigEndian Condition="'$(Platform)' == 's390x'">true</IsBigEndian>
     <Is64Bit Condition="'$(Platform)' == 'arm64' or '$(Platform)' == 'x64' or '$(Platform)' == 's390x' or '$(Platform)' == 'loongarch64' or '$(Platform)' == 'ppc64le' or '$(Platform)' == 'riscv64'">true</Is64Bit>
-    <UseMinimalGlobalizationData Condition="'$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true' or '$(TargetsBrowser)' == 'true' or '$(TargetsWasi)' == 'true'">true</UseMinimalGlobalizationData>
+    <UseMinimalGlobalizationData Condition="'$(TargetsBrowser)' == 'true' or '$(TargetsWasi)' == 'true'">true</UseMinimalGlobalizationData>
   </PropertyGroup>
   <PropertyGroup>
     <DefineConstants Condition="'$(IsBigEndian)' == 'true'">$(DefineConstants);BIGENDIAN</DefineConstants>
@@ -1272,7 +1272,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZone.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.AdjustmentRule.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.cs" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.cs" Condition="'$(UseMinimalGlobalizationData)' != 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.StringSerializer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.TransitionTime.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneNotFoundException.cs" />
@@ -1357,10 +1357,10 @@
     <Compile Include="$(CommonPath)Interop\Interop.ResultCode.cs">
       <Link>Common\Interop\Interop.ResultCode.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneDisplayNameType.cs">
+    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneDisplayNameType.cs" Condition="'$(UseMinimalGlobalizationData)' != 'true'">
       <Link>Common\Interop\Interop.TimeZoneDisplayNameType.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneInfo.cs">
+    <Compile Include="$(CommonPath)Interop\Interop.TimeZoneInfo.cs" Condition="'$(UseMinimalGlobalizationData)' != 'true'">
       <Link>Common\Interop\Interop.TimeZoneInfo.cs</Link>
     </Compile>
     <Compile Include="$(CommonPath)Interop\Interop.TimeZoneInfo.iOS.cs" Condition="'$(IsiOSLike)' == 'true'">
@@ -2476,7 +2476,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.Android.cs" Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsLinuxBionic)' == 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.NonAndroid.cs" Condition="'$(TargetsAndroid)' != 'true' and '$(TargetsLinuxBionic)' != 'true'" />
-    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.Unix.cs" />
+    
   </ItemGroup>
   <ItemGroup Condition="('$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' or '$(TargetsWasi)' == 'true') and '$(IsOSXLike)' != 'true'">
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\FileStatus.SetTimes.OtherUnix.cs" />
@@ -2504,6 +2504,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.iOS.cs" Condition="'$(IsiOSLike)' == 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.OSVersion.Unix.cs" Condition="'$(IsOSXLike)' != 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Environment.SunOS.cs" Condition="'$(Targetsillumos)' == 'true' or '$(TargetsSolaris)' == 'true'" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.FullGlobalizationData.Unix.cs" Condition="'$(UseMinimalGlobalizationData)' != 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\DriveInfoInternal.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\PersistedFiles.Unix.cs" />
   </ItemGroup>
@@ -2519,6 +2520,9 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\PersistedFiles.Browser.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Runtime\InteropServices\RuntimeInformation.Browser.cs" />
   </ItemGroup>
+  <ItemGroup Condition="'$(UseMinimalGlobalizationData)' == 'true'">
+    <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.MinimalGlobalizationData.cs" />
+  </ItemGroup>
   <ItemGroup Condition="'$(IsOSXLike)' == 'true'">
     <Compile Include="$(CommonPath)Interop\OSX\Interop.libobjc.cs">
       <Link>Common\Interop\OSX\Interop.libobjc.cs</Link>
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index 2660dd8b01ab9c..aba934dfed64a9 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -29,10 +29,7 @@ public sealed partial class TimeZoneInfo
         private static string GetUtcStandardDisplayName()
         {
             System.Diagnostics.Debug.Write("TimeZoneInfo.GetUtcStandardDisplayName is called.\n");
-#if TARGET_BROWSER || TARGET_WASI
-            // For this target, be consistent with other time zone display names that use an abbreviation.
-            return "UTC";
-#elif TARGET_IOS || TARGET_TVOS
+#if TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
             {
                 // For this target, be consistent with other time zone display names that use an abbreviation.
@@ -59,10 +56,7 @@ private static string GetUtcStandardDisplayName()
         // Helper function to get the full display name for the UTC static time zone instance
         private static string GetUtcFullDisplayName(string timeZoneId, string standardDisplayName)
         {
-#if TARGET_BROWSER || TARGET_WASI
-            // For this target, be consistent with other time zone display names that use the ID.
-            return $"(UTC) {timeZoneId}";
-#elif TARGET_IOS || TARGET_TVOS
+#if TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
             {
                 // For this target, be consistent with other time zone display names that use the ID.
@@ -116,7 +110,7 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                 {
                     fixed (char* bufferPtr = buffer)
                     {
-#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+#if TARGET_IOS || TARGET_TVOS
                         if (GlobalizationMode.Hybrid)
                             return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
 #endif
@@ -136,7 +130,7 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                     {
                         fixed (char* bufferPtr = buffer)
                         {
-#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+#if TARGET_IOS || TARGET_TVOS
                             if (GlobalizationMode.Hybrid)
                                 return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
 #endif
@@ -285,7 +279,7 @@ private static string GetExemplarCityName(string timeZoneId, string uiCultureNam
         // Helper function that returns an alternative ID using ICU data. Used primarily for converting from Windows IDs.
         private static unsafe string? GetAlternativeId(string id, out bool idIsIana)
         {
-#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+#if TARGET_IOS || TARGET_TVOS
             // No alternative IDs in this target.
             idIsIana = false;
             return null;
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs.cs
new file mode 100644
index 00000000000000..b04b616d4f5db8
--- /dev/null
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs.cs
@@ -0,0 +1,47 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System
+{
+    public sealed partial class TimeZoneInfo
+    {
+#pragma warning disable IDE0060
+        static partial void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan baseUtcOffset, ref string? displayName);
+
+        static partial void GetStandardDisplayName(string timeZoneId, ref string? displayName);
+
+        static partial void GetDaylightDisplayName(string timeZoneId, ref string? displayName);
+
+        private static string GetUtcStandardDisplayName()
+        {
+            // For this target, be consistent with other time zone display names that use an abbreviation.
+            return "UTC";
+        }
+
+        private static string GetUtcFullDisplayName(string timeZoneId, string standardDisplayName)
+        {
+            // For this target, be consistent with other time zone display names that use the ID.
+            return $"(UTC) {timeZoneId}";
+        }
+
+        private static string? GetAlternativeId(string id, out bool idIsIana)
+        {
+            // No alternative IDs in this target.
+            idIsIana = false;
+            return null;
+        }
+
+        private static unsafe bool TryConvertIanaIdToWindowsId(string ianaId, bool allocate, out string? windowsId)
+        {
+            windowsId = null;
+            return false;
+        }
+
+        private static unsafe bool TryConvertWindowsIdToIanaId(string windowsId, string? region, bool allocate,  out string? ianaId)
+        {
+            ianaId = null;
+            return false;
+        }
+#pragma warning restore IDE0060
+    }
+}
\ No newline at end of file
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
index e5a36bee754e9b..312a9734653793 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
@@ -231,7 +231,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return displayName;
 
-#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER  || TARGET_WASI
+#if TARGET_IOS || TARGET_TVOS
             return displayName;
 #else
             GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
@@ -248,7 +248,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return standardDisplayName;
 
-#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+#if TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
                 return standardDisplayName;
 #endif
@@ -266,7 +266,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return daylightDisplayName;
 
-#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+#if TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
                 return daylightDisplayName;
 #endif

From 21acbca21ed07c25eda7e8993eaac18ccb7740f5 Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Fri, 1 Sep 2023 15:15:29 +0200
Subject: [PATCH 06/14] Fix wasm build

---
 .../System.Private.CoreLib.Shared.projitems   |  1 -
 ... TimeZoneInfo.MinimalGlobalizationData.cs} |  2 +-
 .../src/System/TimeZoneInfo.Unix.cs           |  2 ++
 .../pal_timeZoneInfo.m                        | 24 +++++++------------
 4 files changed, 12 insertions(+), 17 deletions(-)
 rename src/libraries/System.Private.CoreLib/src/System/{TimeZoneInfo.MinimalGlobalizationData.cs.cs => TimeZoneInfo.MinimalGlobalizationData.cs} (99%)

diff --git a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
index 2b30fdc91f6bd8..f2601f6184967d 100644
--- a/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
+++ b/src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems
@@ -2476,7 +2476,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.Android.cs" Condition="'$(TargetsAndroid)' == 'true' or '$(TargetsLinuxBionic)' == 'true'" />
     <Compile Include="$(MSBuildThisFileDirectory)System\TimeZoneInfo.Unix.NonAndroid.cs" Condition="'$(TargetsAndroid)' != 'true' and '$(TargetsLinuxBionic)' != 'true'" />
-    
   </ItemGroup>
   <ItemGroup Condition="('$(TargetsUnix)' == 'true' or '$(TargetsBrowser)' == 'true' or '$(TargetsWasi)' == 'true') and '$(IsOSXLike)' != 'true'">
     <Compile Include="$(MSBuildThisFileDirectory)System\IO\FileStatus.SetTimes.OtherUnix.cs" />
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs
similarity index 99%
rename from src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs.cs
rename to src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs
index b04b616d4f5db8..fa1d25e4933352 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.MinimalGlobalizationData.cs
@@ -44,4 +44,4 @@ private static unsafe bool TryConvertWindowsIdToIanaId(string windowsId, string?
         }
 #pragma warning restore IDE0060
     }
-}
\ No newline at end of file
+}
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
index 312a9734653793..521f7e361d9250 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
@@ -235,6 +235,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             return displayName;
 #else
             GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
+
             return displayName;
 #endif
         }
@@ -271,6 +272,7 @@ public AdjustmentRule[] GetAdjustmentRules()
                 return daylightDisplayName;
 #endif
             GetDaylightDisplayName(Id, ref daylightDisplayName);
+
             return daylightDisplayName;
         }
 
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
index b9776af63fb636..b6e07ddd0b6ef4 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
@@ -38,42 +38,36 @@ int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeN
         switch (type)
         {
             case TimeZoneDisplayName_Standard:
-                style = NSTimeZoneNameStyleStandard;//;NSTimeZoneNameStyleShortStandard
+                style = NSTimeZoneNameStyleStandard;
                 break;
             case TimeZoneDisplayName_DaylightSavings:
-                style = NSTimeZoneNameStyleDaylightSaving;//;NSTimeZoneNameStyleShortDaylightSaving
+                style = NSTimeZoneNameStyleDaylightSaving;
                 break;
             case TimeZoneDisplayName_Generic:
-                style = NSTimeZoneNameStyleGeneric;//;NSTimeZoneNameStyleShortGeneric
+                style = NSTimeZoneNameStyleGeneric;
                 break;
-            // case TimeZoneDisplayName_GenericLocation:
-            //     style = NSTimeZoneNameStyleStandard;//???
-            //     break;
-            // case TimeZoneDisplayName_ExemplarCity:
-            //     style = NSTimeZoneNameStyleStandard;//??
-            //     break;
             default:
-                return UnknownError;//-1;
+                return UnknownError;
         }
 
         NSString* timeZoneName = [timeZone localizedName:style locale:currentLocale];
         if (timeZoneName == NULL || timeZoneName.length == 0)
         {
-            return UnknownError;//0
+            return UnknownError;
         }
 
-        int32_t index = 0, dstIdx = 0, isError = 0;
+        int32_t index = 0, dstIdx = 0, resultCode = Success;
         uint16_t dstCodepoint;
         while (index < timeZoneName.length)
         {
             dstCodepoint = [timeZoneName characterAtIndex: index];
-            Append(result, dstIdx, resultLength, dstCodepoint, isError);
+            Append(result, dstIdx, resultLength, dstCodepoint, resultCode);
             index++;
         }
         dstCodepoint = '\0';
-        Append(result, dstIdx, resultLength, dstCodepoint, isError);
+        Append(result, dstIdx, resultLength, dstCodepoint, resultCode);
 
-        return isError ? UnknownError : Success;//timeZoneName.length;//;
+        return resultCode;
     }
 }
 #endif

From 4947b49852abad62337c15a0e96e7204e61e6756 Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Fri, 1 Sep 2023 16:07:48 +0200
Subject: [PATCH 07/14] Minor fix

---
 .../src/System/TimeZoneInfo.FullGlobalizationData.cs          | 4 ++--
 src/libraries/System.Runtime/System.Runtime.sln               | 2 --
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
index 6c2e3a962526ec..b1cc58e3dd01d7 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
@@ -9,7 +9,7 @@ public sealed partial class TimeZoneInfo
     {
         private static unsafe bool TryConvertIanaIdToWindowsId(string ianaId, bool allocate, out string? windowsId)
         {
-#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+#if TARGET_IOS || TARGET_TVOS
                 windowsId = null;
                 return false;
 #else
@@ -37,7 +37,7 @@ ianaId is null ||
 
         private static unsafe bool TryConvertWindowsIdToIanaId(string windowsId, string? region, bool allocate,  out string? ianaId)
         {
-#if TARGET_IOS || TARGET_TVOS || TARGET_BROWSER || TARGET_WASI
+#if TARGET_IOS || TARGET_TVOS
             ianaId = null;
             return false;
 #else
diff --git a/src/libraries/System.Runtime/System.Runtime.sln b/src/libraries/System.Runtime/System.Runtime.sln
index 4ef7e0094581f3..a7d50d4a347abd 100644
--- a/src/libraries/System.Runtime/System.Runtime.sln
+++ b/src/libraries/System.Runtime/System.Runtime.sln
@@ -27,8 +27,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.Nls.Tests",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.Tests", "tests\System.Runtime.Tests.csproj", "{4EE36055-AD7C-4779-B3F6-08687960DCC3}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.IOS.Tests", "tests\Hybrid\System.Runtime.IOS.Tests.csproj", "{4EE36055-AD7C-4779-B3F6-08687960DCC3}"
-EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.ReflectionInvokeEmit.Tests", "tests\System\Reflection\InvokeEmit\System.Runtime.ReflectionInvokeEmit.Tests.csproj", "{C3F25EEF-04B4-407A-960B-0C1CE9C04430}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Runtime.ReflectionInvokeInterpreted.Tests", "tests\System\Reflection\InvokeInterpreted\System.Runtime.ReflectionInvokeInterpreted.Tests.csproj", "{47E26787-7C27-4572-AD8B-868DE44E2C48}"

From 32e90d83aeab0b7e5c71a41eaf0263cb291f4f6d Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Fri, 1 Sep 2023 16:27:41 +0200
Subject: [PATCH 08/14] Remove logging

---
 .../src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs | 1 -
 .../libs/System.Globalization.Native/pal_timeZoneInfo.m   | 8 ++------
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index aba934dfed64a9..8f9a0503bd7fcf 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -28,7 +28,6 @@ public sealed partial class TimeZoneInfo
         // Helper function to get the standard display name for the UTC static time zone instance
         private static string GetUtcStandardDisplayName()
         {
-            System.Diagnostics.Debug.Write("TimeZoneInfo.GetUtcStandardDisplayName is called.\n");
 #if TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
             {
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
index b6e07ddd0b6ef4..dc3144a01a045f 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
@@ -2,22 +2,18 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 //
 
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdlib.h>
-
 #include "pal_errors_internal.h"
 #include "pal_locale_internal.h"
 #include "pal_timeZoneInfo.h"
-
 #import <Foundation/Foundation.h>
+
 #if defined(TARGET_MACCATALYST) || defined(TARGET_IOS) || defined(TARGET_TVOS)
 
 /*
 Gets the localized display name that is currently in effect for the specified time zone.
 */
 int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeName, int32_t lNameLength, const uint16_t* timeZoneId, int32_t timeZoneIdLength,
-                                                      TimeZoneDisplayNameType type, uint16_t* result, int32_t resultLength)
+                                                         TimeZoneDisplayNameType type, uint16_t* result, int32_t resultLength)
 {
     @autoreleasepool
     {

From 88088d8a95a283583c464ab2bd2b650bcac089cc Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Tue, 5 Sep 2023 11:58:05 +0200
Subject: [PATCH 09/14] Fix failure on maccatalyst

---
 .../System/TimeZoneInfo.FullGlobalizationData.Unix.cs  | 10 +++++-----
 .../src/System/TimeZoneInfo.FullGlobalizationData.cs   |  4 ++--
 .../src/System/TimeZoneInfo.Unix.NonAndroid.cs         |  2 +-
 .../src/System/TimeZoneInfo.Unix.cs                    |  6 +++---
 .../System.Runtime/tests/System/TimeZoneInfoTests.cs   |  4 ++--
 5 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index 8f9a0503bd7fcf..3854243e4bb8d3 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -28,7 +28,7 @@ public sealed partial class TimeZoneInfo
         // Helper function to get the standard display name for the UTC static time zone instance
         private static string GetUtcStandardDisplayName()
         {
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
             {
                 // For this target, be consistent with other time zone display names that use an abbreviation.
@@ -55,7 +55,7 @@ private static string GetUtcStandardDisplayName()
         // Helper function to get the full display name for the UTC static time zone instance
         private static string GetUtcFullDisplayName(string timeZoneId, string standardDisplayName)
         {
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
             {
                 // For this target, be consistent with other time zone display names that use the ID.
@@ -109,7 +109,7 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                 {
                     fixed (char* bufferPtr = buffer)
                     {
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
                         if (GlobalizationMode.Hybrid)
                             return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
 #endif
@@ -129,7 +129,7 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
                     {
                         fixed (char* bufferPtr = buffer)
                         {
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
                             if (GlobalizationMode.Hybrid)
                                 return Interop.Globalization.GetTimeZoneDisplayNameNative(locale, locale.Length, id, id.Length, type, bufferPtr, buffer.Length);
 #endif
@@ -278,7 +278,7 @@ private static string GetExemplarCityName(string timeZoneId, string uiCultureNam
         // Helper function that returns an alternative ID using ICU data. Used primarily for converting from Windows IDs.
         private static unsafe string? GetAlternativeId(string id, out bool idIsIana)
         {
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
             // No alternative IDs in this target.
             idIsIana = false;
             return null;
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
index b1cc58e3dd01d7..b79848bcd36109 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
@@ -9,7 +9,7 @@ public sealed partial class TimeZoneInfo
     {
         private static unsafe bool TryConvertIanaIdToWindowsId(string ianaId, bool allocate, out string? windowsId)
         {
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
                 windowsId = null;
                 return false;
 #else
@@ -37,7 +37,7 @@ ianaId is null ||
 
         private static unsafe bool TryConvertWindowsIdToIanaId(string windowsId, string? region, bool allocate,  out string? ianaId)
         {
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
             ianaId = null;
             return false;
 #else
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.NonAndroid.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.NonAndroid.cs
index f90b52bdc52053..885acc9cef882c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.NonAndroid.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.NonAndroid.cs
@@ -511,7 +511,7 @@ private static bool TryGetLocalTzFile([NotNullWhen(true)] out byte[]? rawData, [
 #pragma warning disable IDE0074 // Use compound assignment
             if (tzVariable == null)
             {
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
                 tzVariable = Interop.Sys.GetDefaultTimeZone();
 #elif TARGET_WASI || TARGET_BROWSER
                 if (UseEmbeddedTzDatabase)
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
index 521f7e361d9250..967a01aaaf8072 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
@@ -231,7 +231,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return displayName;
 
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
             return displayName;
 #else
             GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
@@ -249,7 +249,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return standardDisplayName;
 
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
                 return standardDisplayName;
 #endif
@@ -267,7 +267,7 @@ public AdjustmentRule[] GetAdjustmentRules()
             if (GlobalizationMode.Invariant)
                 return daylightDisplayName;
 
-#if TARGET_IOS || TARGET_TVOS
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
             if (!GlobalizationMode.Hybrid)
                 return daylightDisplayName;
 #endif
diff --git a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
index c44010cf2618ca..d70407ffb5b274 100644
--- a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
+++ b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
@@ -89,7 +89,7 @@ public static void Names()
         //  Name abbreviations, if available, are used instead
         public static IEnumerable<object[]> Platform_TimeZoneNamesTestData()
         {
-            if (PlatformDetection.IsBrowser || (!PlatformDetection.IsHybridGlobalizationOnOSX  && (PlatformDetection.IsiOS || PlatformDetection.IstvOS)))
+            if (PlatformDetection.IsBrowser || (!PlatformDetection.IsHybridGlobalizationOnOSX  && (PlatformDetection.IsMacCatalyst || PlatformDetection.IsiOS || PlatformDetection.IstvOS)))
                 return new TheoryData<TimeZoneInfo, string, string, string, string>
                 {
                     { TimeZoneInfo.FindSystemTimeZoneById(s_strPacific), "(UTC-08:00) America/Los_Angeles", null, "PST", "PDT" },
@@ -100,7 +100,7 @@ public static IEnumerable<object[]> Platform_TimeZoneNamesTestData()
                     { s_NewfoundlandTz, "(UTC-03:30) America/St_Johns", null, "NST", "NDT" },
                     { s_catamarcaTz, "(UTC-03:00) America/Argentina/Catamarca", null, "-03", "-02" }
                 };
-            else if(PlatformDetection.IsHybridGlobalizationOnOSX && (PlatformDetection.IsiOS || PlatformDetection.IstvOS))
+            else if (PlatformDetection.IsHybridGlobalizationOnOSX && (PlatformDetection.IsMacCatalyst || PlatformDetection.IsiOS || PlatformDetection.IstvOS))
                 return new TheoryData<TimeZoneInfo, string, string, string, string>
                 {
                     { TimeZoneInfo.FindSystemTimeZoneById(s_strPacific), "(UTC-08:00) America/Los_Angeles", null, "Pacific Standard Time", "Pacific Daylight Time" },

From a886791658256f64fb664471fdcd00f0ebd91e41 Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Tue, 5 Sep 2023 18:38:18 +0200
Subject: [PATCH 10/14] Changed displayName for hybrid mode

---
 .../Interop.TimeZoneDisplayNameType.cs        |  1 +
 ...TimeZoneInfo.FullGlobalizationData.Unix.cs | 20 ++++--
 .../src/System/TimeZoneInfo.Unix.cs           |  6 +-
 .../tests/System/TimeZoneInfoTests.cs         |  4 +-
 .../pal_normalization.m                       |  4 ++
 .../pal_timeZoneInfo.h                        |  1 +
 .../pal_timeZoneInfo.m                        | 61 +++++++++++--------
 7 files changed, 62 insertions(+), 35 deletions(-)

diff --git a/src/libraries/Common/src/Interop/Interop.TimeZoneDisplayNameType.cs b/src/libraries/Common/src/Interop/Interop.TimeZoneDisplayNameType.cs
index 570eb0eb4b1ecd..698cdd54aebdf7 100644
--- a/src/libraries/Common/src/Interop/Interop.TimeZoneDisplayNameType.cs
+++ b/src/libraries/Common/src/Interop/Interop.TimeZoneDisplayNameType.cs
@@ -13,6 +13,7 @@ internal enum TimeZoneDisplayNameType
             DaylightSavings = 2,
             GenericLocation = 3,
             ExemplarCity = 4,
+            TimeZoneName = 5,
         }
     }
 }
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index 3854243e4bb8d3..e88430c3fb6dfc 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -153,13 +153,27 @@ private static unsafe void GetDisplayName(string timeZoneId, Interop.Globalizati
         // Helper function that builds the value backing the DisplayName field from globalization data.
         private static void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan baseUtcOffset, ref string? displayName)
         {
+            CultureInfo uiCulture = UICulture;
+            // Get the base offset to prefix in front of the time zone.
+            // Only UTC and its aliases have "(UTC)", handled earlier.  All other zones include an offset, even if it's zero.
+            string baseOffsetText = string.Create(null, stackalloc char[128], $"(UTC{(baseUtcOffset >= TimeSpan.Zero ? '+' : '-')}{baseUtcOffset:hh\\:mm})");
+
+#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
+            if (GlobalizationMode.Hybrid)
+            {
+                string? timeZoneName = null;
+                GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.TimeZoneName, uiCulture.Name, ref timeZoneName);
+                // For this target, be consistent with other time zone display names that use the ID.
+                displayName = $"{baseOffsetText} {timeZoneName}";
+                return;
+            }
+#endif
             // There are a few different ways we might show the display name depending on the data.
             // The algorithm used below should avoid duplicating the same words while still achieving the
             // goal of providing a unique, discoverable, and intuitive name.
 
             // Try to get the generic name for this time zone.
             string? genericName = null;
-            CultureInfo uiCulture = UICulture;
             GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.Generic, uiCulture.Name, ref genericName);
             if (genericName == null)
             {
@@ -167,10 +181,6 @@ private static void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan
                 return;
             }
 
-            // Get the base offset to prefix in front of the time zone.
-            // Only UTC and its aliases have "(UTC)", handled earlier.  All other zones include an offset, even if it's zero.
-            string baseOffsetText = string.Create(null, stackalloc char[128], $"(UTC{(baseUtcOffset >= TimeSpan.Zero ? '+' : '-')}{baseUtcOffset:hh\\:mm})");
-
             // Get the generic location name.
             string? genericLocationName = null;
             GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.GenericLocation, uiCulture.Name, ref genericLocationName);
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
index 967a01aaaf8072..d6b370b7210a60 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
@@ -232,12 +232,12 @@ public AdjustmentRule[] GetAdjustmentRules()
                 return displayName;
 
 #if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
-            return displayName;
-#else
+            if (!GlobalizationMode.Hybrid)
+                return displayName;
+#endif
             GetFullValueForDisplayNameField(Id, BaseUtcOffset, ref displayName);
 
             return displayName;
-#endif
         }
 
         private string? PopulateStandardDisplayName()
diff --git a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
index d70407ffb5b274..88ea3476b4f2ed 100644
--- a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
+++ b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
@@ -88,7 +88,7 @@ public static void Names()
         //  Due to ICU size limitations, full daylight/standard names are not included for the browser.
         //  Name abbreviations, if available, are used instead
         public static IEnumerable<object[]> Platform_TimeZoneNamesTestData()
-        {
+        {//
             if (PlatformDetection.IsBrowser || (!PlatformDetection.IsHybridGlobalizationOnOSX  && (PlatformDetection.IsMacCatalyst || PlatformDetection.IsiOS || PlatformDetection.IstvOS)))
                 return new TheoryData<TimeZoneInfo, string, string, string, string>
                 {
@@ -147,7 +147,7 @@ public static void Platform_TimeZoneNames(TimeZoneInfo tzi, string displayName,
                     displayName = displayName.Replace(c.ToString(), "", StringComparison.Ordinal);
                 }
             }
-
+            System.Diagnostics.Debug.WriteLine($"Platform_TimeZoneNames Display Name: '{tzi.DisplayName}'");
             Assert.True(displayName == tzi.DisplayName || alternativeDisplayName == tzi.DisplayName,
                          $"Display Name: Neither '{displayName}' nor '{alternativeDisplayName}' equal to '{tzi.DisplayName}'");
             Assert.Equal(standardName, tzi.StandardName);
diff --git a/src/native/libs/System.Globalization.Native/pal_normalization.m b/src/native/libs/System.Globalization.Native/pal_normalization.m
index c31242ca36ef31..62c3ecde53c9d0 100644
--- a/src/native/libs/System.Globalization.Native/pal_normalization.m
+++ b/src/native/libs/System.Globalization.Native/pal_normalization.m
@@ -7,6 +7,10 @@
 #include "pal_normalization.h"
 #import <Foundation/Foundation.h>
 
+#if !__has_feature(objc_arc)
+#error This file relies on ARC for memory management, but ARC is not enabled.
+#endif
+
 #if defined(TARGET_MACCATALYST) || defined(TARGET_IOS) || defined(TARGET_TVOS)
 static NSString* GetNormalizedStringForForm(NormalizationForm normalizationForm, NSString* sourceString)
 {
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
index 28a00e89186a77..99653b939196e2 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.h
@@ -18,6 +18,7 @@ typedef enum
     TimeZoneDisplayName_DaylightSavings = 2,
     TimeZoneDisplayName_GenericLocation = 3,
     TimeZoneDisplayName_ExemplarCity = 4,
+    TimeZoneDisplayName_TimeZoneName = 5,
 } TimeZoneDisplayNameType;
 
 PALEXPORT int32_t GlobalizationNative_WindowsIdToIanaId(const UChar* windowsId, const char* region, UChar* ianaId, int32_t ianaIdLength);
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
index dc3144a01a045f..5eb3d736f405fc 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
@@ -7,6 +7,10 @@
 #include "pal_timeZoneInfo.h"
 #import <Foundation/Foundation.h>
 
+#if !__has_feature(objc_arc)
+#error This file relies on ARC for memory management, but ARC is not enabled.
+#endif
+
 #if defined(TARGET_MACCATALYST) || defined(TARGET_IOS) || defined(TARGET_TVOS)
 
 /*
@@ -17,36 +21,43 @@ int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeN
 {
     @autoreleasepool
     {
-        NSLocale *currentLocale;
-        if(localeName == NULL || lNameLength == 0)
-        {
-            currentLocale = [NSLocale systemLocale];
-        }
-        else
-        {
-            NSString *locName = [NSString stringWithCharacters: localeName length: lNameLength];
-            currentLocale = [NSLocale localeWithLocaleIdentifier:locName];
-        }
         NSString* tzName = [NSString stringWithCharacters: timeZoneId length: timeZoneIdLength];
         NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:tzName];
-        NSTimeZoneNameStyle style;
+        NSString* timeZoneName;
 
-        switch (type)
+        if (type == TimeZoneDisplayName_TimeZoneName)
+            timeZoneName = timeZone.name;
+        else
         {
-            case TimeZoneDisplayName_Standard:
-                style = NSTimeZoneNameStyleStandard;
-                break;
-            case TimeZoneDisplayName_DaylightSavings:
-                style = NSTimeZoneNameStyleDaylightSaving;
-                break;
-            case TimeZoneDisplayName_Generic:
-                style = NSTimeZoneNameStyleGeneric;
-                break;
-            default:
-                return UnknownError;
-        }
+            NSLocale *currentLocale;
+            if(localeName == NULL || lNameLength == 0)
+            {
+                currentLocale = [NSLocale systemLocale];
+            }
+            else
+            {
+                NSString *locName = [NSString stringWithCharacters: localeName length: lNameLength];
+                currentLocale = [NSLocale localeWithLocaleIdentifier:locName];
+            }
+            NSTimeZoneNameStyle style;
 
-        NSString* timeZoneName = [timeZone localizedName:style locale:currentLocale];
+            switch (type)
+            {
+                case TimeZoneDisplayName_Standard:
+                    style = NSTimeZoneNameStyleStandard;
+                    break;
+                case TimeZoneDisplayName_DaylightSavings:
+                    style = NSTimeZoneNameStyleDaylightSaving;
+                    break;
+                case TimeZoneDisplayName_Generic:
+                    style = NSTimeZoneNameStyleGeneric;
+                    break;
+                default:
+                    return UnknownError;
+            }
+
+            timeZoneName = [timeZone localizedName:style locale:currentLocale];
+        }
         if (timeZoneName == NULL || timeZoneName.length == 0)
         {
             return UnknownError;

From 8d9143034eb090a8453639dae80935d0c05fca73 Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Tue, 5 Sep 2023 18:48:49 +0200
Subject: [PATCH 11/14] Remove logs

---
 .../System.Runtime/tests/System/TimeZoneInfoTests.cs          | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
index 88ea3476b4f2ed..d70407ffb5b274 100644
--- a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
+++ b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
@@ -88,7 +88,7 @@ public static void Names()
         //  Due to ICU size limitations, full daylight/standard names are not included for the browser.
         //  Name abbreviations, if available, are used instead
         public static IEnumerable<object[]> Platform_TimeZoneNamesTestData()
-        {//
+        {
             if (PlatformDetection.IsBrowser || (!PlatformDetection.IsHybridGlobalizationOnOSX  && (PlatformDetection.IsMacCatalyst || PlatformDetection.IsiOS || PlatformDetection.IstvOS)))
                 return new TheoryData<TimeZoneInfo, string, string, string, string>
                 {
@@ -147,7 +147,7 @@ public static void Platform_TimeZoneNames(TimeZoneInfo tzi, string displayName,
                     displayName = displayName.Replace(c.ToString(), "", StringComparison.Ordinal);
                 }
             }
-            System.Diagnostics.Debug.WriteLine($"Platform_TimeZoneNames Display Name: '{tzi.DisplayName}'");
+
             Assert.True(displayName == tzi.DisplayName || alternativeDisplayName == tzi.DisplayName,
                          $"Display Name: Neither '{displayName}' nor '{alternativeDisplayName}' equal to '{tzi.DisplayName}'");
             Assert.Equal(standardName, tzi.StandardName);

From 4d9b1f6adb364c448b423309794f332798f8f8fe Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Wed, 6 Sep 2023 10:43:45 +0200
Subject: [PATCH 12/14] Changes requested by review

---
 ...TimeZoneInfo.FullGlobalizationData.Unix.cs | 19 ++++++++++---------
 .../pal_timeZoneInfo.m                        |  6 ++++--
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index e88430c3fb6dfc..693a6ad187ebf4 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -11,6 +11,7 @@ public sealed partial class TimeZoneInfo
     {
         private const string InvariantUtcStandardDisplayName = "Coordinated Universal Time";
         private const string FallbackCultureName = "en-US";
+#if !TARGET_MACCATALYST && TARGET_IOS && TARGET_TVOS
         private const string GmtId = "GMT";
 
         // Some time zones may give better display names using their location names rather than their generic name.
@@ -22,6 +23,7 @@ public sealed partial class TimeZoneInfo
             "Pacific/Apia",       // Prefer "Samoa Time" over "Apia Time"
             "Pacific/Pitcairn"    // Prefer "Pitcairn Islands Time" over "Pitcairn Time"
         };
+#endif
 
         private static CultureInfo? _uiCulture;
 
@@ -159,15 +161,13 @@ private static void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan
             string baseOffsetText = string.Create(null, stackalloc char[128], $"(UTC{(baseUtcOffset >= TimeSpan.Zero ? '+' : '-')}{baseUtcOffset:hh\\:mm})");
 
 #if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
-            if (GlobalizationMode.Hybrid)
-            {
-                string? timeZoneName = null;
-                GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.TimeZoneName, uiCulture.Name, ref timeZoneName);
-                // For this target, be consistent with other time zone display names that use the ID.
-                displayName = $"{baseOffsetText} {timeZoneName}";
-                return;
-            }
-#endif
+            Debug.Assert(GlobalizationMode.Hybrid);
+            string? timeZoneName = null;
+            GetDisplayName(timeZoneId, Interop.Globalization.TimeZoneDisplayNameType.TimeZoneName, uiCulture.Name, ref timeZoneName);
+            // For this target, be consistent with other time zone display names that use the ID.
+            displayName = $"{baseOffsetText} {timeZoneName}";
+            return;
+#else
             // There are a few different ways we might show the display name depending on the data.
             // The algorithm used below should avoid duplicating the same words while still achieving the
             // goal of providing a unique, discoverable, and intuitive name.
@@ -267,6 +267,7 @@ private static void GetFullValueForDisplayNameField(string timeZoneId, TimeSpan
 
                 displayName = $"{baseOffsetText} {genericName} ({exemplarCityName})";
             }
+#endif
         }
 
         // Helper function that gets an exmplar city name either from ICU or from the IANA time zone ID itself
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
index 5eb3d736f405fc..d05c6fa9eebe7b 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
@@ -3,7 +3,7 @@
 //
 
 #include "pal_errors_internal.h"
-#include "pal_locale_internal.h"
+#include "pal_icushim_internal.h"
 #include "pal_timeZoneInfo.h"
 #import <Foundation/Foundation.h>
 
@@ -30,7 +30,7 @@ int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeN
         else
         {
             NSLocale *currentLocale;
-            if(localeName == NULL || lNameLength == 0)
+            if (localeName == NULL || lNameLength == 0)
             {
                 currentLocale = [NSLocale systemLocale];
             }
@@ -69,6 +69,8 @@ int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeN
         {
             dstCodepoint = [timeZoneName characterAtIndex: index];
             Append(result, dstIdx, resultLength, dstCodepoint, resultCode);
+            if (resultCode != Success)
+                return resultCode;
             index++;
         }
         dstCodepoint = '\0';

From a64ee2b509f02a8d59b234759580a5ed6c0cede2 Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Wed, 6 Sep 2023 13:29:46 +0200
Subject: [PATCH 13/14] Fix build failure

---
 .../src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index 693a6ad187ebf4..9d69737220fc6e 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -11,7 +11,7 @@ public sealed partial class TimeZoneInfo
     {
         private const string InvariantUtcStandardDisplayName = "Coordinated Universal Time";
         private const string FallbackCultureName = "en-US";
-#if !TARGET_MACCATALYST && TARGET_IOS && TARGET_TVOS
+#if !TARGET_MACCATALYST && !TARGET_IOS && !TARGET_TVOS
         private const string GmtId = "GMT";
 
         // Some time zones may give better display names using their location names rather than their generic name.

From c589bbef27b3447271313dba975d6bfedc626dd1 Mon Sep 17 00:00:00 2001
From: Meri Khamoyan <merikhamoyan@microsoft.com>
Date: Wed, 6 Sep 2023 17:48:18 +0200
Subject: [PATCH 14/14] Add checks and remove not needed code

---
 .../src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs   | 6 ------
 .../src/System/TimeZoneInfo.FullGlobalizationData.cs        | 4 ++--
 .../libs/System.Globalization.Native/pal_timeZoneInfo.m     | 4 ++++
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
index 9d69737220fc6e..1703114fabea37 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.Unix.cs
@@ -289,14 +289,8 @@ private static string GetExemplarCityName(string timeZoneId, string uiCultureNam
         // Helper function that returns an alternative ID using ICU data. Used primarily for converting from Windows IDs.
         private static unsafe string? GetAlternativeId(string id, out bool idIsIana)
         {
-#if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
-            // No alternative IDs in this target.
-            idIsIana = false;
-            return null;
-#else
             idIsIana = false;
             return TryConvertWindowsIdToIanaId(id, null, out string? ianaId) ? ianaId : null;
-#endif
         }
     }
 }
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
index b79848bcd36109..06bffad9f31515 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.FullGlobalizationData.cs
@@ -10,8 +10,8 @@ public sealed partial class TimeZoneInfo
         private static unsafe bool TryConvertIanaIdToWindowsId(string ianaId, bool allocate, out string? windowsId)
         {
 #if TARGET_MACCATALYST || TARGET_IOS || TARGET_TVOS
-                windowsId = null;
-                return false;
+            windowsId = null;
+            return false;
 #else
             if (GlobalizationMode.Invariant ||
                 GlobalizationMode.UseNls ||
diff --git a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
index d05c6fa9eebe7b..1cd51dc6704ffd 100644
--- a/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
+++ b/src/native/libs/System.Globalization.Native/pal_timeZoneInfo.m
@@ -23,6 +23,10 @@ int32_t GlobalizationNative_GetTimeZoneDisplayNameNative(const uint16_t* localeN
     {
         NSString* tzName = [NSString stringWithCharacters: timeZoneId length: timeZoneIdLength];
         NSTimeZone* timeZone = [NSTimeZone timeZoneWithName:tzName];
+        if (timeZone == NULL)
+        {
+            return UnknownError;
+        }
         NSString* timeZoneName;
 
         if (type == TimeZoneDisplayName_TimeZoneName)