Fix more compatiable timezone problem.

framework/Volo.Abp.sln

@@ -485,6 +485,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Volo.Abp.BlobStoring.Bunny"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Volo.Abp.BlobStoring.Bunny.Tests", "test\Volo.Abp.BlobStoring.Bunny.Tests\Volo.Abp.BlobStoring.Bunny.Tests.csproj", "{BC4BB2D6-DFD8-4190-AAC3-32C0A7A8E915}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Volo.Abp.Timing.Tests", "test\Volo.Abp.Timing.Tests\Volo.Abp.Timing.Tests.csproj", "{58FCF22D-E8DB-4EB8-B586-9BB6E9899D64}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -1447,6 +1449,10 @@ Global
 		{BC4BB2D6-DFD8-4190-AAC3-32C0A7A8E915}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{BC4BB2D6-DFD8-4190-AAC3-32C0A7A8E915}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{BC4BB2D6-DFD8-4190-AAC3-32C0A7A8E915}.Release|Any CPU.Build.0 = Release|Any CPU
+		{58FCF22D-E8DB-4EB8-B586-9BB6E9899D64}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{58FCF22D-E8DB-4EB8-B586-9BB6E9899D64}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{58FCF22D-E8DB-4EB8-B586-9BB6E9899D64}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{58FCF22D-E8DB-4EB8-B586-9BB6E9899D64}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -1691,6 +1697,7 @@ Global
 		{C753DDD6-5699-45F8-8669-08CE0BB816DE} = {447C8A77-E5F0-4538-8687-7383196D04EA}
 		{1BBCBA72-CDB6-4882-96EE-D4CD149433A2} = {5DF0E140-0513-4D0D-BE2E-3D4D85CD70E6}
 		{BC4BB2D6-DFD8-4190-AAC3-32C0A7A8E915} = {447C8A77-E5F0-4538-8687-7383196D04EA}
+		{58FCF22D-E8DB-4EB8-B586-9BB6E9899D64} = {447C8A77-E5F0-4538-8687-7383196D04EA}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {BB97ECF4-9A84-433F-A80B-2A3285BDD1D5}

framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/DatePicker/AbpDatePickerBaseTagHelperService.cs

@@ -54,7 +54,7 @@ public abstract class AbpDatePickerBaseTagHelperService<TTagHelper> : AbpTagHelp
                 {
                     if(x is string s && DateTime.TryParse(s, out var dt))
                     {
-                        return Clock.Convert(dt).ToString("O");
+                        return Clock.ConvertTo(dt).ToString("O");
                     }
 
                     return string.Empty;
@@ -65,7 +65,7 @@ public abstract class AbpDatePickerBaseTagHelperService<TTagHelper> : AbpTagHelp
                 {
                     if(x is DateTime dt && dt != default)
                     {
-                        return Clock.Convert(dt).ToString("O");
+                        return Clock.ConvertTo(dt).ToString("O");
                     }
 
                     return string.Empty;
@@ -76,7 +76,7 @@ public abstract class AbpDatePickerBaseTagHelperService<TTagHelper> : AbpTagHelp
                 {
                     if(x is DateTime dt && dt != default)
                     {
-                        return Clock.Convert(dt).ToString("O");
+                        return Clock.ConvertTo(dt).ToString("O");
                     }
                     return string.Empty;
                 }
@@ -86,7 +86,7 @@ public abstract class AbpDatePickerBaseTagHelperService<TTagHelper> : AbpTagHelp
                 {
                     if(x is DateTimeOffset dto && dto != default)
                     {
-                        return Clock.Convert(dto).ToString("O");
+                        return Clock.ConvertTo(dto).DateTime.ToString("O");
                     }
 
                     return string.Empty;
@@ -97,7 +97,7 @@ public abstract class AbpDatePickerBaseTagHelperService<TTagHelper> : AbpTagHelp
                 {
                     if(x is DateTimeOffset dto && dto != default)
                     {
-                        return Clock.Convert(dto).ToString("O");
+                        return Clock.ConvertTo(dto).DateTime.ToString("O");
                     }
 
                     return string.Empty;

framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/DatePicker/AbpDatePickerTagHelperService.cs

@@ -53,13 +53,23 @@ public class AbpDatePickerTagHelperService : AbpDatePickerBaseTagHelperService<A
                 For = TagHelper.AspFor
             };
 
-            var attributes = new TagHelperAttributeList { { "data-date", "true" }, { "type", "hidden" } };
+            var attributes = new TagHelperAttributeList { { "data-hidden-datepicker", "true" }, { "data-date", "true" }, { "type", "hidden" } };
 
-            if (Clock.SupportsMultipleTimezone && TagHelper.AspFor.Model is DateTime dateTime)
+            if (Clock.SupportsMultipleTimezone)
             {
-                DateTagHelper.Format = "{0:O}";
+                if (TagHelper.AspFor.Model is DateTime dateTime)
-                DateTagHelper.Value = Clock.Convert(dateTime).ToString("O");
+                {
-                attributes.Add("value", DateTagHelper.Value);
+                    DateTagHelper.Format = "{0:O}";
+                    DateTagHelper.Value = Clock.ConvertTo(dateTime).ToString("O");
+                    attributes.Add("value", DateTagHelper.Value);
+                }
+
+                if (TagHelper.AspFor.Model is DateTimeOffset dateTimeOffset)
+                {
+                    DateTagHelper.Format = "{0:O}";
+                    DateTagHelper.Value = Clock.ConvertTo(dateTimeOffset).UtcDateTime.ToString("O");
+                    attributes.Add("value", DateTagHelper.Value);
+                }
             }
 
             DateTagHelperOutput = await DateTagHelper.ProcessAndGetOutputAsync(attributes, context, "input");

framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/DatePicker/AbpDateRangePickerTagHelperService.cs

@@ -38,7 +38,7 @@ public class AbpDateRangePickerTagHelperService : AbpDatePickerBaseTagHelperServ
     {
         if (TagHelper.AspForStart != null)
         {
-            var startDateAttributes = new TagHelperAttributeList { { "data-start-date", "true" }, { "type", "hidden" } };
+            var startDateAttributes = new TagHelperAttributeList { { "data-hidden-datepicker", "true" }, { "data-start-date", "true" }, { "type", "hidden" } };
             StartDateTagHelper = new InputTagHelper(Generator)
             {
                 ViewContext = TagHelper.ViewContext,
@@ -46,11 +46,21 @@ public class AbpDateRangePickerTagHelperService : AbpDatePickerBaseTagHelperServ
                 InputTypeName = "hidden"
             };
 
-            if (Clock.SupportsMultipleTimezone && TagHelper.AspForStart.Model is DateTime dateTime)
+            if (Clock.SupportsMultipleTimezone)
             {
-                StartDateTagHelper.Format = "{0:O}";
+                if (TagHelper.AspForStart.Model is DateTime dateTime)
-                StartDateTagHelper.Value = Clock.Convert(dateTime).ToString("O");
+                {
-                startDateAttributes.Add("value", StartDateTagHelper.Value);
+                    StartDateTagHelper.Format = "{0:O}";
+                    StartDateTagHelper.Value = Clock.ConvertTo(dateTime).ToString("O");
+                    startDateAttributes.Add("value", StartDateTagHelper.Value);
+                }
+
+                if (TagHelper.AspForStart.Model is DateTimeOffset dateTimeOffset)
+                {
+                    StartDateTagHelper.Format = "{0:O}";
+                    StartDateTagHelper.Value = Clock.ConvertTo(dateTimeOffset).UtcDateTime.ToString("O");
+                    startDateAttributes.Add("value", StartDateTagHelper.Value);
+                }
             }
 
             StartDateTagHelperOutput = await StartDateTagHelper.ProcessAndGetOutputAsync(startDateAttributes, context, "input");
@@ -58,7 +68,7 @@ public class AbpDateRangePickerTagHelperService : AbpDatePickerBaseTagHelperServ
 
         if (TagHelper.AspForEnd != null)
         {
-            var endDateAttributes = new TagHelperAttributeList { { "data-end-date", "true" }, { "type", "hidden" } };
+            var endDateAttributes = new TagHelperAttributeList { { "data-hidden-datepicker", "true" }, { "data-end-date", "true" }, { "type", "hidden" } };
             EndDateTagHelper = new InputTagHelper(Generator)
             {
                 ViewContext = TagHelper.ViewContext,
@@ -66,11 +76,21 @@ public class AbpDateRangePickerTagHelperService : AbpDatePickerBaseTagHelperServ
                 InputTypeName = "hidden"
             };
 
-            if (Clock.SupportsMultipleTimezone && TagHelper.AspForEnd.Model is DateTime dateTime)
+            if (Clock.SupportsMultipleTimezone)
             {
-                EndDateTagHelper.Format = "{0:O}";
+                if (TagHelper.AspForEnd.Model is DateTime dateTime)
-                EndDateTagHelper.Value = Clock.Convert(dateTime).ToString("O");
+                {
-                endDateAttributes.Add("value", EndDateTagHelper.Value);
+                    EndDateTagHelper.Format = "{0:O}";
+                    EndDateTagHelper.Value = Clock.ConvertTo(dateTime).ToString("O");
+                    endDateAttributes.Add("value", EndDateTagHelper.Value);
+                }
+
+                if (TagHelper.AspForEnd.Model is DateTimeOffset dateTimeOffset)
+                {
+                    EndDateTagHelper.Format = "{0:O}";
+                    EndDateTagHelper.Value = Clock.ConvertTo(dateTimeOffset).UtcDateTime.ToString("O");
+                    endDateAttributes.Add("value", EndDateTagHelper.Value);
+                }
             }
 
             EndDateTagHelperOutput = await EndDateTagHelper.ProcessAndGetOutputAsync(endDateAttributes, context, "input");

framework/src/Volo.Abp.Timing/Volo/Abp/Timing/Clock.cs

@@ -26,6 +26,11 @@ public class Clock : IClock, ITransientDependency
 
     public virtual bool SupportsMultipleTimezone => Options.Kind == DateTimeKind.Utc;
 
+    /// <summary>
+    /// Normalizes given <see cref="DateTime"/>.
+    /// </summary>
+    /// <param name="dateTime">DateTime to be normalized.</param>
+    /// <returns>Normalized DateTime</returns>
     public virtual DateTime Normalize(DateTime dateTime)
     {
         if (Kind == DateTimeKind.Unspecified || Kind == dateTime.Kind)
@@ -46,7 +51,12 @@ public class Clock : IClock, ITransientDependency
         return DateTime.SpecifyKind(dateTime, Kind);
     }
 
-    public virtual DateTime Convert(DateTime dateTime)
+    /// <summary>
+    /// Converts given UTC <see cref="DateTime"/> to user's time zone.
+    /// </summary>
+    /// <param name="dateTime">DateTime to be normalized.</param>
+    /// <returns>Converted DateTime</returns>
+    public virtual DateTime ConvertTo(DateTime dateTime)
     {
         if (!SupportsMultipleTimezone ||
             dateTime.Kind != DateTimeKind.Utc ||
@@ -59,7 +69,12 @@ public class Clock : IClock, ITransientDependency
         return TimeZoneInfo.ConvertTime(dateTime, timezoneInfo);
     }
 
-    public virtual DateTimeOffset Convert(DateTimeOffset dateTimeOffset)
+    /// <summary>
+    /// Converts given <see cref="DateTimeOffset"/> to user's time zone.
+    /// </summary>
+    /// <param name="dateTimeOffset">DateTimeOffset to be normalized.</param>
+    /// <returns>Converted DateTimeOffset</returns>
+    public virtual DateTimeOffset ConvertTo(DateTimeOffset dateTimeOffset)
     {
         if (!SupportsMultipleTimezone ||
             CurrentTimezoneProvider.TimeZone.IsNullOrWhiteSpace())
@@ -70,4 +85,28 @@ public class Clock : IClock, ITransientDependency
         var timezoneInfo = TimezoneProvider.GetTimeZoneInfo(CurrentTimezoneProvider.TimeZone);
         return TimeZoneInfo.ConvertTime(dateTimeOffset, timezoneInfo);
     }
+
+    /// <summary>
+    /// Converts given user's <see cref="DateTime"/> to UTC or not.
+    /// </summary>
+    /// <param name="dateTime">DateTime to be normalized.</param>
+    /// <returns>Converted DateTime</returns>
+    public DateTime ConvertFrom(DateTime dateTime)
+    {
+        if (!SupportsMultipleTimezone ||
+            CurrentTimezoneProvider.TimeZone.IsNullOrWhiteSpace())
+        {
+            return dateTime;
+        }
+
+        var timezoneInfo = TimezoneProvider.GetTimeZoneInfo(CurrentTimezoneProvider.TimeZone);
+        var targetDateTime = dateTime;
+        if (dateTime.Kind == DateTimeKind.Utc)
+        {
+            return dateTime;
+        }
+
+        targetDateTime = DateTime.SpecifyKind(targetDateTime, DateTimeKind.Unspecified);
+        return TimeZoneInfo.ConvertTimeToUtc(targetDateTime, timezoneInfo);
+    }
 }

framework/src/Volo.Abp.Timing/Volo/Abp/Timing/IClock.cs

@@ -27,16 +27,23 @@ public interface IClock
     DateTime Normalize(DateTime dateTime);
 
     /// <summary>
-    /// Converts given <see cref="DateTime"/> to user's time zone.
+    /// Converts given UTC <see cref="DateTime"/> to user's time zone.
     /// </summary>
     /// <param name="dateTime">DateTime to be normalized.</param>
     /// <returns>Converted DateTime</returns>
-    DateTime Convert(DateTime dateTime);
+    DateTime ConvertTo(DateTime dateTime);
 
     /// <summary>
     /// Converts given <see cref="DateTimeOffset"/> to user's time zone.
     /// </summary>
     /// <param name="dateTimeOffset">DateTimeOffset to be normalized.</param>
     /// <returns>Converted DateTimeOffset</returns>
-    DateTimeOffset Convert(DateTimeOffset dateTimeOffset);
+    DateTimeOffset ConvertTo(DateTimeOffset dateTimeOffset);
+
+    /// <summary>
+    /// Converts given user's <see cref="DateTime"/> to UTC or not.
+    /// </summary>
+    /// <param name="dateTime">DateTime to be normalized.</param>
+    /// <returns>Converted DateTime</returns>
+    DateTime ConvertFrom(DateTime dateTime);
 }

framework/test/Volo.Abp.Timing.Tests/Volo.Abp.Timing.Tests.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <Import Project="..\..\..\common.test.props" />
+
+    <PropertyGroup>
+        <TargetFramework>net9.0</TargetFramework>
+        <RootNamespace />
+    </PropertyGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\..\src\Volo.Abp.Timing\Volo.Abp.Timing.csproj" />
+        <ProjectReference Include="..\AbpTestBase\AbpTestBase.csproj" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    </ItemGroup>
+
+</Project>

framework/test/Volo.Abp.Timing.Tests/Volo/Abp/Timing/AbpTimingTestModule.cs

@@ -0,0 +1,14 @@
+using Volo.Abp.Modularity;
+
+namespace Volo.Abp.Timing;
+
+[DependsOn(
+    typeof(AbpTimingModule),
+    typeof(AbpTestBaseModule)
+)]
+public class AbpTimingTestModule : AbpModule
+{
+    public override void ConfigureServices(ServiceConfigurationContext context)
+    {
+    }
+}

framework/test/Volo.Abp.Timing.Tests/Volo/Abp/Timing/Clock_Default_Tests.cs

@@ -0,0 +1,110 @@
+using System;
+using Shouldly;
+using Volo.Abp.Testing;
+using Xunit;
+
+namespace Volo.Abp.Timing;
+
+public class Clock_Default_Tests : AbpIntegratedTest<AbpTimingTestModule>
+{
+    private readonly IClock _clock;
+    private readonly ICurrentTimezoneProvider _currentTimezoneProvider;
+
+    public Clock_Default_Tests()
+    {
+        _clock = GetRequiredService<IClock>();
+        _currentTimezoneProvider = GetRequiredService<ICurrentTimezoneProvider>();
+    }
+
+    [Fact]
+    public void ConvertTo_Test()
+    {
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Utc);
+            var convertedDateTime = _clock.ConvertTo(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Utc);
+            convertedDateTime.ToString("O").ShouldBe("2025-03-01T05:30:00.0000000Z");
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Local);
+            var convertedDateTime = _clock.ConvertTo(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Local);
+            convertedDateTime.ToString("O").ShouldBe(dateTime.ToString("O"));
+        }
+
+        using(_currentTimezoneProvider.Change(null))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Local);
+            var convertedDateTime = _clock.ConvertTo(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Local);
+            convertedDateTime.ToString("O").ShouldBe(dateTime.ToString("O"));
+        }
+    }
+
+    [Fact]
+    public void ConvertTo_DateTimeOffset_Test()
+    {
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Utc), TimeSpan.Zero);
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.Zero);
+            convertedDateTimeOffset.ShouldBe(dateTimeOffset);
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified), TimeSpan.Zero);
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.Zero);
+            convertedDateTimeOffset.ShouldBe(dateTimeOffset);
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified), TimeSpan.FromHours(3));
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.FromHours(3));
+            convertedDateTimeOffset.ShouldBe(dateTimeOffset);
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified), TimeSpan.FromHours(8));
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.FromHours(8));
+            convertedDateTimeOffset.ShouldBe(dateTimeOffset);
+        }
+    }
+
+    [Fact]
+    public void ConvertFrom_Test()
+    {
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified);
+            var convertedDateTime = _clock.ConvertFrom(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Unspecified);
+            convertedDateTime.ShouldBe(dateTime);
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Local);
+            var convertedDateTime = _clock.ConvertFrom(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Local);
+            convertedDateTime.ShouldBe(dateTime);
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Utc);
+            var convertedDateTime = _clock.ConvertFrom(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Utc);
+            convertedDateTime.ShouldBe(dateTime);
+        }
+    }
+}

framework/test/Volo.Abp.Timing.Tests/Volo/Abp/Timing/Clock_Utc_Tests.cs

@@ -0,0 +1,132 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using Shouldly;
+using Volo.Abp.Testing;
+using Xunit;
+
+namespace Volo.Abp.Timing;
+
+public class Clock_Utc_Tests : AbpIntegratedTest<AbpTimingTestModule>
+{
+    private readonly IClock _clock;
+    private readonly ICurrentTimezoneProvider _currentTimezoneProvider;
+
+    public Clock_Utc_Tests()
+    {
+        _clock = GetRequiredService<IClock>();
+        _currentTimezoneProvider = GetRequiredService<ICurrentTimezoneProvider>();
+    }
+
+    protected override void AfterAddApplication(IServiceCollection services)
+    {
+        services.Configure<AbpClockOptions>(options =>
+        {
+            options.Kind = DateTimeKind.Utc;
+        });
+        base.AfterAddApplication(services);
+    }
+
+    [Fact]
+    public void ConvertTo_Test()
+    {
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Utc);
+            var convertedDateTime = _clock.ConvertTo(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Unspecified);
+            convertedDateTime.ToString("O").ShouldBe("2025-03-01T08:30:00.0000000"); //Without Z
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            // ConvertTo will not convert the DateTimeKind.Local
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Local);
+            var convertedDateTime = _clock.ConvertTo(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Local);
+            convertedDateTime.ToString("O").ShouldBe(dateTime.ToString("O"));
+        }
+
+        using(_currentTimezoneProvider.Change(null))
+        {
+            // ConvertTo will not convert if the timezone is not set
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Local);
+            var convertedDateTime = _clock.ConvertTo(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Local);
+            convertedDateTime.ToString("O").ShouldBe(dateTime.ToString("O"));
+        }
+    }
+
+    [Fact]
+    public void ConvertTo_DateTimeOffset_Test()
+    {
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Utc), TimeSpan.Zero);
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.FromHours(3));
+            convertedDateTimeOffset.ToString("O").ShouldBe("2025-03-01T08:30:00.0000000+03:00");
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified), TimeSpan.Zero);
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.FromHours(3));
+            convertedDateTimeOffset.ToString("O").ShouldBe("2025-03-01T08:30:00.0000000+03:00");
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified), TimeSpan.FromHours(3));
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.FromHours(3));
+            convertedDateTimeOffset.ShouldBe(dateTimeOffset);
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified), TimeSpan.FromHours(8));
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.FromHours(3));
+            convertedDateTimeOffset.DateTime.ShouldBe(new DateTime(2025, 3, 1, 0, 30, 0, DateTimeKind.Unspecified));
+        }
+
+        using(_currentTimezoneProvider.Change(null))
+        {
+            // ConvertTo will not convert if the timezone is not set
+            var dateTimeOffset = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified), TimeSpan.FromHours(8));
+            var convertedDateTimeOffset = _clock.ConvertTo(dateTimeOffset);
+            convertedDateTimeOffset.Offset.ShouldBe(TimeSpan.FromHours(8));
+            convertedDateTimeOffset.ShouldBe(dateTimeOffset);
+        }
+    }
+
+    [Fact]
+    public void ConvertFrom_Test()
+    {
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified);
+            var convertedDateTime = _clock.ConvertFrom(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Utc);
+            convertedDateTime.ToString("O").ShouldBe("2025-03-01T02:30:00.0000000Z");
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Local);
+            var convertedDateTime = _clock.ConvertFrom(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Utc);
+            convertedDateTime.ToString("O").ShouldBe("2025-03-01T02:30:00.0000000Z");
+        }
+
+        using(_currentTimezoneProvider.Change("Europe/Istanbul"))
+        {
+            var dateTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Utc);
+            var convertedDateTime = _clock.ConvertFrom(dateTime);
+            convertedDateTime.Kind.ShouldBe(DateTimeKind.Utc);
+            convertedDateTime.ToString("O").ShouldBe("2025-03-01T05:30:00.0000000Z");
+        }
+    }
+
+}

npm/packs/core/src/abp.js

@@ -775,7 +775,7 @@ var abp = abp || {};
         if (abp.clock.supportsMultipleTimezone()) {
             var timeZone = abp.clock.timeZone();
             var now = new Date();
-            var formattedDate = now.toLocaleString('en-US', { timeZone: timeZone, timeZoneName: 'short' });
+            var formattedDate = now.toLocaleString('en-US', { timeZone: timeZone, timeZoneName: 'longOffset' });
             var match = formattedDate.match(/GMT([+-]\d+)/);
             var targetOffsetHours = match ? parseInt(match[1], 10) : 0;
             var dateObj = new Date(dateObj.getTime() - (targetOffsetHours * 60 * 60 * 1000));
@@ -805,14 +805,15 @@ var abp = abp || {};
             return dateString;
         }
 
+        var culture = abp.localization.currentCulture.cultureName;
+        options = Object.assign({}, abp.clock.toLocaleStringOptions, options || {});
         if (abp.clock.supportsMultipleTimezone()) {
             var timezone = abp.clock.timeZone();
             if (timezone) {
-                options = options || {};
+                return date.toLocaleString(culture, Object.assign({}, options, { timeZone: timezone }));
-                return date.toLocaleString(abp.localization.currentCulture.cultureName, Object.assign({}, abp.clock.toLocaleStringOptions, options, { timeZone: timezone }));
             }
         }
-        return date.toLocaleString();
+        return date.toLocaleString(culture, options);
     }
 
     /* FEATURES *************************************************/

npm/packs/luxon/src/abp.luxon.js

@@ -43,4 +43,56 @@ var abp = abp || {};
         return form;
     }
 
+    // Normalize Date object or date string to standard string format that will be sent to server
+    abp.clock.normalizeToString = function (date) {
+        if (!date) {
+            return date;
+        }
+
+        var dateObj = date instanceof Date ? date : new Date(date);
+        if (isNaN(dateObj)) {
+            return date;
+        }
+
+        var timeZone = abp.clock.timeZone();
+        if (abp.clock.supportsMultipleTimezone() && timeZone) {
+            return DateTime.fromObject({
+                year: dateObj.getFullYear(),
+                month: dateObj.getMonth() + 1,
+                day: dateObj.getDate(),
+                hour: dateObj.getHours(),
+                minute: dateObj.getMinutes(),
+                second: dateObj.getSeconds()
+            }, { zone: timeZone }).setZone("utc").toISO();
+        } else {
+            return luxon.DateTime.fromJSDate(dateObj).toFormat("yyyy-MM-dd'T'HH:mm:ss");
+        }
+    };
+
+    // Normalize date string to locale date string that will be displayed to user
+    abp.clock.normalizeToLocaleString = function (dateString, options) {
+        if (!dateString) {
+            return dateString;
+        }
+
+        var date = new Date(dateString);
+        if (isNaN(date)) {
+            return dateString;
+        }
+
+        options = options || luxon.DateTime.DATETIME_FULL;
+        if (abp.clock.supportsMultipleTimezone()) {
+            var timezone = abp.clock.timeZone();
+            if (timezone) {
+                return luxon.DateTime.fromJSDate(date)
+                    .setZone(timezone)
+                    .setLocale(abp.localization.currentCulture.cultureName)
+                    .toLocaleString(Object.assign({}, abp.clock.toLocaleStringOptions, options));
+            }
+        }
+
+        return luxon.DateTime.fromJSDate(date)
+                    .setLocale(abp.localization.currentCulture.cultureName)
+                    .toLocaleString(Object.assign({}, abp.clock.toLocaleStringOptions, options));
+    }
 })(jQuery);