Add Switch.Microsoft.AspNetCore.Mvc.UseDateTimeTypeForDateTimeOffset quirks mode

- patch recipients can use switch to undo the #6648 fix

src/Microsoft.AspNetCore.Mvc.TagHelpers/InputTagHelper.cs

@@ -18,6 +18,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
     [HtmlTargetElement("input", Attributes = ForAttributeName, TagStructure = TagStructure.WithoutEndTag)]
     public class InputTagHelper : TagHelper
     {
+        internal const string UseDateTimeLocalTypeForDateTimeOffsetSwitch = "Switch.Microsoft.AspNetCore.Mvc.UseDateTimeLocalTypeForDateTimeOffset";
         private const string ForAttributeName = "asp-for";
         private const string FormatAttributeName = "asp-format";
 
@@ -63,6 +64,14 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 { "time", "{0:HH:mm:ss.fff}" },
             };
 
+        static InputTagHelper()
+        {
+            if (AppContext.TryGetSwitch(UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled) && enabled)
+            {
+                _defaultInputTypes.Remove(nameof(DateTimeOffset));
+            }
+        }
+
         /// <summary>
         /// Creates a new <see cref="InputTagHelper"/>.
         /// </summary>
@@ -393,8 +402,14 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             {
                 // Rfc3339 mode _may_ override EditFormatString in a limited number of cases. Happens only when
                 // EditFormatString has a default format i.e. came from a [DataType] attribute.
+                //
+                // First condition may occur when Switch.Microsoft.AspNetCore.Mvc.UseDateTimeLocalTypeForDateTimeOffset
+                // is true in extremely rare cases: The <input/> element for a DateTimeOffset expression must have
+                // type ="text". Checking the switch again to remove that case.
                 if (string.Equals("text", inputType) &&
-                    string.Equals(nameof(DateTimeOffset), inputTypeHint, StringComparison.OrdinalIgnoreCase))
+                    string.Equals(nameof(DateTimeOffset), inputTypeHint, StringComparison.OrdinalIgnoreCase) &&
+                    !(AppContext.TryGetSwitch(UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled) &&
+                      enabled))
                 {
                     // Auto-select a format that round-trips Offset and sub-Second values in a DateTimeOffset. Not
                     // done if user chose the "text" type in .cshtml file or with data annotations i.e. when

src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewFeatures/TemplateRenderer.cs

@@ -17,9 +17,10 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
 {
     public class TemplateRenderer
     {
+        public const string IEnumerableOfIFormFileName = "IEnumerable`" + nameof(IFormFile);
+        internal const string UseDateTimeLocalTypeForDateTimeOffsetSwitch = "Switch.Microsoft.AspNetCore.Mvc.UseDateTimeLocalTypeForDateTimeOffset";
         private const string DisplayTemplateViewPath = "DisplayTemplates";
         private const string EditorTemplateViewPath = "EditorTemplates";
-        public const string IEnumerableOfIFormFileName = "IEnumerable`" + nameof(IFormFile);
 
         private static readonly Dictionary<string, Func<IHtmlHelper, IHtmlContent>> _defaultDisplayActions =
             new Dictionary<string, Func<IHtmlHelper, IHtmlContent>>(StringComparer.OrdinalIgnoreCase)
@@ -75,6 +76,14 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
         private readonly string _templateName;
         private readonly bool _readOnly;
 
+        static TemplateRenderer()
+        {
+            if (AppContext.TryGetSwitch(UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled) && enabled)
+            {
+                _defaultEditorActions.Remove(nameof(DateTimeOffset));
+            }
+        }
+
         public TemplateRenderer(
             IViewEngine viewEngine,
             IViewBufferScope bufferScope,

test/Microsoft.AspNetCore.Mvc.FunctionalTests/HtmlHelperOptionsTest.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.Net.Http;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Testing;
@@ -10,6 +11,8 @@ namespace Microsoft.AspNetCore.Mvc.FunctionalTests
 {
     public class HtmlHelperOptionsTest : IClassFixture<MvcTestFixture<RazorWebSite.Startup>>
     {
+        private const string UseDateTimeLocalTypeForDateTimeOffsetSwitch = "Switch.Microsoft.AspNetCore.Mvc.UseDateTimeLocalTypeForDateTimeOffset";
+
         public HtmlHelperOptionsTest(MvcTestFixture<RazorWebSite.Startup> fixture)
         {
             Client = fixture.Client;
@@ -21,14 +24,17 @@ namespace Microsoft.AspNetCore.Mvc.FunctionalTests
         public async Task AppWideDefaultsInViewAndPartialView()
         {
             // Arrange
+            AppContext.TryGetSwitch(UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+            var expectedType = enabled ? "datetime-local" : "text";
+            var expectedOffset = enabled ? string.Empty : "&#x2B;00:00";
             var expected =
-@"<div class=""validation-summary-errors""><validationSummaryElement>MySummary</validationSummaryElement>
+$@"<div class=""validation-summary-errors""><validationSummaryElement>MySummary</validationSummaryElement>
 <ul><li>A model error occurred.</li>
 </ul></div>
 <validationMessageElement class=""field-validation-error"">An error occurred.</validationMessageElement>
 <input id=""Prefix!Property1"" name=""Prefix.Property1"" type=""text"" value="""" />
 <div class=""editor-label""><label for=""MyDate"">MyDate</label></div>
-<div class=""editor-field""><input class=""text-box single-line"" id=""MyDate"" name=""MyDate"" type=""text"" value=""2000-01-02T03:04:05.060&#x2B;00:00"" /> </div>
+<div class=""editor-field""><input class=""text-box single-line"" id=""MyDate"" name=""MyDate"" type=""{expectedType}"" value=""2000-01-02T03:04:05.060{expectedOffset}"" /> </div>
 
 <div class=""validation-summary-errors""><validationSummaryElement>MySummary</validationSummaryElement>
 <ul><li>A model error occurred.</li>
@@ -36,7 +42,7 @@ namespace Microsoft.AspNetCore.Mvc.FunctionalTests
 <validationMessageElement class=""field-validation-error"">An error occurred.</validationMessageElement>
 <input id=""Prefix!Property1"" name=""Prefix.Property1"" type=""text"" value="""" />
 <div class=""editor-label""><label for=""MyDate"">MyDate</label></div>
-<div class=""editor-field""><input class=""text-box single-line"" id=""MyDate"" name=""MyDate"" type=""text"" value=""2000-01-02T03:04:05.060&#x2B;00:00"" /> </div>
+<div class=""editor-field""><input class=""text-box single-line"" id=""MyDate"" name=""MyDate"" type=""{expectedType}"" value=""2000-01-02T03:04:05.060{expectedOffset}"" /> </div>
 
 False";
 
@@ -52,14 +58,16 @@ False";
         public async Task OverrideAppWideDefaultsInViewAndPartialView()
         {
             // Arrange
+            AppContext.TryGetSwitch(UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+            var expectedType = enabled ? "datetime-local" : "text";
             var expected =
-@"<div class=""validation-summary-errors""><ValidationSummaryInView>MySummary</ValidationSummaryInView>
+$@"<div class=""validation-summary-errors""><ValidationSummaryInView>MySummary</ValidationSummaryInView>
 <ul><li>A model error occurred.</li>
 </ul></div>
 <ValidationInView class=""field-validation-error"" data-valmsg-for=""Error"" data-valmsg-replace=""true"">An error occurred.</ValidationInView>
 <input id=""Prefix!Property1"" name=""Prefix.Property1"" type=""text"" value="""" />
 <div class=""editor-label""><label for=""MyDate"">MyDate</label></div>
-<div class=""editor-field""><input class=""text-box single-line"" data-val=""true"" data-val-required=""The MyDate field is required."" id=""MyDate"" name=""MyDate"" type=""text"" value=""02/01/2000 03:04:05 &#x2B;00:00"" /> <ValidationInView class=""field-validation-valid"" data-valmsg-for=""MyDate"" data-valmsg-replace=""true""></ValidationInView></div>
+<div class=""editor-field""><input class=""text-box single-line"" data-val=""true"" data-val-required=""The MyDate field is required."" id=""MyDate"" name=""MyDate"" type=""{expectedType}"" value=""02/01/2000 03:04:05 &#x2B;00:00"" /> <ValidationInView class=""field-validation-valid"" data-valmsg-for=""MyDate"" data-valmsg-replace=""true""></ValidationInView></div>
 
 True
 <div class=""validation-summary-errors""><ValidationSummaryInPartialView>MySummary</ValidationSummaryInPartialView>
@@ -68,7 +76,7 @@ True
 <ValidationInPartialView class=""field-validation-error"" data-valmsg-for=""Error"" data-valmsg-replace=""true"">An error occurred.</ValidationInPartialView>
 <input id=""Prefix!Property1"" name=""Prefix.Property1"" type=""text"" value="""" />
 <div class=""editor-label""><label for=""MyDate"">MyDate</label></div>
-<div class=""editor-field""><input class=""text-box single-line"" id=""MyDate"" name=""MyDate"" type=""text"" value=""02/01/2000 03:04:05 &#x2B;00:00"" /> <ValidationInPartialView class=""field-validation-valid"" data-valmsg-for=""MyDate"" data-valmsg-replace=""true""></ValidationInPartialView></div>
+<div class=""editor-field""><input class=""text-box single-line"" id=""MyDate"" name=""MyDate"" type=""{expectedType}"" value=""02/01/2000 03:04:05 &#x2B;00:00"" /> <ValidationInPartialView class=""field-validation-valid"" data-valmsg-for=""MyDate"" data-valmsg-replace=""true""></ValidationInPartialView></div>
 
 True";
 

test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/InputTagHelperTest.cs

@@ -21,7 +21,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
 {
     public class InputTagHelperTest
     {
-        public static TheoryData MultiAttributeCheckBoxData
+        public static TheoryData<TagHelperAttributeList, string> MultiAttributeCheckBoxData
         {
             get
             {
@@ -386,10 +386,22 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             Assert.Equal(expectedTagName, output.TagName);
         }
 
+        public static TheoryData<string, string> Process_GeneratesFormattedOutputData
+        {
+            get
+            {
+                AppContext.TryGetSwitch(InputTagHelper.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+                return new TheoryData<string, string>
+                {
+                    { "datetime", "datetime" },
+                    { null, enabled ? "datetime-local" : "text" },
+                    { "hidden", "hidden" },
+                };
+            }
+        }
+
         [Theory]
-        [InlineData("datetime", "datetime")]
+        [MemberData(nameof(Process_GeneratesFormattedOutputData))]
-        [InlineData(null, "text")]
-        [InlineData("hidden", "hidden")]
         public void Process_GeneratesFormattedOutput(string specifiedType, string expectedType)
         {
             // Arrange
@@ -1206,20 +1218,43 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             Assert.Equal(expectedTagName, output.TagName);
         }
 
+        public static TheoryData<string, Html5DateRenderingMode, string, string> ProcessAsync_CallsGenerateTextBox_AddsExpectedAttributesForRfc3339Data
+        {
+            get
+            {
+                AppContext.TryGetSwitch(InputTagHelper.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+                var expectedK = enabled ? string.Empty : "K";
+                return new TheoryData<string, Html5DateRenderingMode, string, string>
+                {
+                    { "Date", Html5DateRenderingMode.CurrentCulture, "{0:d}", "date" }, // Format from [DataType].
+                    { "Date", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-dd}", "date" },
+                    { "DateTime", Html5DateRenderingMode.CurrentCulture, null, "datetime-local" },
+                    { "DateTime", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-ddTHH:mm:ss.fff}", "datetime-local" },
+                    { "DateTimeOffset", Html5DateRenderingMode.CurrentCulture, null, enabled ? "datetime-local" : "text" },
+                    {
+                        "DateTimeOffset",
+                        Html5DateRenderingMode.Rfc3339,
+                        $"{{0:yyyy-MM-ddTHH:mm:ss.fff{expectedK}}}",
+                        enabled ? "datetime-local" : "text"
+                    },
+                    { "DateTimeLocal", Html5DateRenderingMode.CurrentCulture, null, "datetime-local" },
+                    { "DateTimeLocal", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-ddTHH:mm:ss.fff}", "datetime-local" },
+                    { "Time", Html5DateRenderingMode.CurrentCulture, "{0:t}", "time" }, // Format from [DataType].
+                    { "Time", Html5DateRenderingMode.Rfc3339, "{0:HH:mm:ss.fff}", "time" },
+                    { "NullableDate", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-dd}", "date" },
+                    { "NullableDateTime", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-ddTHH:mm:ss.fff}", "datetime-local" },
+                    {
+                        "NullableDateTimeOffset",
+                        Html5DateRenderingMode.Rfc3339,
+                        $"{{0:yyyy-MM-ddTHH:mm:ss.fff{expectedK}}}",
+                        enabled ? "datetime-local" : "text"
+                    },
+                };
+            }
+        }
+
         [Theory]
-        [InlineData("Date", Html5DateRenderingMode.CurrentCulture, "{0:d}", "date")]    // Format from [DataType].
+        [MemberData(nameof(ProcessAsync_CallsGenerateTextBox_AddsExpectedAttributesForRfc3339Data))]
-        [InlineData("Date", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-dd}", "date")]
-        [InlineData("DateTime", Html5DateRenderingMode.CurrentCulture, null, "datetime-local")]
-        [InlineData("DateTime", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-ddTHH:mm:ss.fff}", "datetime-local")]
-        [InlineData("DateTimeOffset", Html5DateRenderingMode.CurrentCulture, null, "text")]
-        [InlineData("DateTimeOffset", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-ddTHH:mm:ss.fffK}", "text")]
-        [InlineData("DateTimeLocal", Html5DateRenderingMode.CurrentCulture, null, "datetime-local")]
-        [InlineData("DateTimeLocal", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-ddTHH:mm:ss.fff}", "datetime-local")]
-        [InlineData("Time", Html5DateRenderingMode.CurrentCulture, "{0:t}", "time")]    // Format from [DataType].
-        [InlineData("Time", Html5DateRenderingMode.Rfc3339, "{0:HH:mm:ss.fff}", "time")]
-        [InlineData("NullableDate", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-dd}", "date")]
-        [InlineData("NullableDateTime", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-ddTHH:mm:ss.fff}", "datetime-local")]
-        [InlineData("NullableDateTimeOffset", Html5DateRenderingMode.Rfc3339, "{0:yyyy-MM-ddTHH:mm:ss.fffK}", "text")]
         public async Task ProcessAsync_CallsGenerateTextBox_AddsExpectedAttributesForRfc3339(
             string propertyName,
             Html5DateRenderingMode dateRenderingMode,

test/Microsoft.AspNetCore.Mvc.ViewFeatures.Test/Internal/DefaultEditorTemplatesTest.cs

@@ -29,6 +29,10 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
         {
             get
             {
+                AppContext.TryGetSwitch(TemplateRenderer.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+
+                // Tests use string properties and fall back to text template (no type attribute) when quirk is enabled.
+                var dateTimeOffsetType = enabled ? string.Empty : " type='text'";
                 return new TheoryData<string, string>
                 {
                     { null, "__TextBox__ class='text-box single-line'" },
@@ -53,8 +57,8 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
                     { "datetime", "__TextBox__ class='text-box single-line' type='datetime-local'" },
                     { "DateTime-local", "__TextBox__ class='text-box single-line' type='datetime-local'" },
                     { "DATETIME-LOCAL", "__TextBox__ class='text-box single-line' type='datetime-local'" },
-                    { "datetimeoffset", "__TextBox__ class='text-box single-line' type='text'" },
+                    { "datetimeoffset", $"__TextBox__ class='text-box single-line'{dateTimeOffsetType}" },
-                    { "DateTimeOffset", "__TextBox__ class='text-box single-line' type='text'" },
+                    { "DateTimeOffset", $"__TextBox__ class='text-box single-line'{dateTimeOffsetType}" },
                     { "Time", "__TextBox__ class='text-box single-line' type='time'" },
                     { "time", "__TextBox__ class='text-box single-line' type='time'" },
                     { "Byte", "__TextBox__ class='text-box single-line' type='number'" },
@@ -774,9 +778,12 @@ Environment.NewLine;
         {
             // Arrange
             var requiredMessage = ValidationAttributeUtil.GetRequiredErrorMessage("DateTimeOffset");
+            AppContext.TryGetSwitch(TemplateRenderer.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+            var expectedOffset = enabled ? string.Empty : "+00:00";
             var expectedInput = "<input class=\"HtmlEncode[[text-box single-line]]\" data-val=\"HtmlEncode[[true]]\" " +
                 $"data-val-required=\"HtmlEncode[[{requiredMessage}]]\" id=\"HtmlEncode[[FieldPrefix]]\" " +
-                "name=\"HtmlEncode[[FieldPrefix]]\" type=\"HtmlEncode[[datetime]]\" value=\"HtmlEncode[[2000-01-02T03:04:05.060+00:00]]\" />";
+                "name=\"HtmlEncode[[FieldPrefix]]\" type=\"HtmlEncode[[datetime]]\" " +
+                $"value=\"HtmlEncode[[2000-01-02T03:04:05.060{expectedOffset}]]\" />";
 
             var offset = TimeSpan.FromHours(0);
             var model = new DateTimeOffset(
@@ -814,14 +821,32 @@ Environment.NewLine;
             Assert.Equal(expectedInput, HtmlContentUtilities.HtmlContentToString(result));
         }
 
+        public static TheoryData<string, string, string, string> Editor_FindsCorrectDateOrTimeTemplateData
+        {
+            get
+            {
+                AppContext.TryGetSwitch(TemplateRenderer.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+                var expectedOffset = enabled ? string.Empty : "-05:00";
+                return new TheoryData<string, string, string, string>
+                {
+                    { null, null, $"2000-01-02T03:04:05.060{expectedOffset}", enabled ? "datetime-local" : "text" },
+                    { "date", "{0:d}", "2000-01-02", "date" },
+                    { "datetime", null, "2000-01-02T03:04:05.060", "datetime-local" },
+                    { "datetime-local", null, "2000-01-02T03:04:05.060", "datetime-local" },
+                    {
+                        "DateTimeOffset",
+                        "{0:o}",
+                        $"2000-01-02T03:04:05.060{expectedOffset}",
+                        enabled ? "datetime-local" : "text"
+                    },
+                    { "time", "{0:t}", "03:04:05.060", "time" },
+                };
+            }
+        }
+
         // Html5DateRenderingMode.Rfc3339 is enabled by default.
         [Theory]
-        [InlineData(null, null, "2000-01-02T03:04:05.060-05:00", "text")]
+        [MemberData(nameof(Editor_FindsCorrectDateOrTimeTemplateData))]
-        [InlineData("date", "{0:d}", "2000-01-02", "date")]
-        [InlineData("datetime", null, "2000-01-02T03:04:05.060", "datetime-local")]
-        [InlineData("datetime-local", null, "2000-01-02T03:04:05.060", "datetime-local")]
-        [InlineData("DateTimeOffset", "{0:o}", "2000-01-02T03:04:05.060-05:00", "text")]
-        [InlineData("time", "{0:t}", "03:04:05.060", "time")]
         public void Editor_FindsCorrectDateOrTimeTemplate(
             string dataTypeName,
             string editFormatString,
@@ -875,14 +900,26 @@ Environment.NewLine;
             Assert.Equal(expectedInput, HtmlContentUtilities.HtmlContentToString(result));
         }
 
+        public static TheoryData<string, string, string, string> Editor_FindsCorrectDateOrTimeTemplate_NotRfc3339Data
+        {
+            get
+            {
+                AppContext.TryGetSwitch(TemplateRenderer.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+                return new TheoryData<string, string, string, string>
+                {
+                    { null, null, "02/01/2000 03:04:05 -05:00", enabled ? "datetime-local" : "text" },
+                    { "date", "{0:d}", "02/01/2000", "date" },
+                    { "datetime", null, "02/01/2000 03:04:05 -05:00", "datetime-local" },
+                    { "datetime-local", null, "02/01/2000 03:04:05 -05:00", "datetime-local" },
+                    { "DateTimeOffset", "{0:o}", "2000-01-02T03:04:05.0600000-05:00", enabled ? "datetime-local" : "text" },
+                    { "time", "{0:t}", "03:04", "time" },
+                };
+            }
+        }
+
         // Html5DateRenderingMode.Rfc3339 can be disabled.
         [Theory]
-        [InlineData(null, null, "02/01/2000 03:04:05 -05:00", "text")]
+        [MemberData(nameof(Editor_FindsCorrectDateOrTimeTemplate_NotRfc3339Data))]
-        [InlineData("date", "{0:d}", "02/01/2000", "date")]
-        [InlineData("datetime", null, "02/01/2000 03:04:05 -05:00", "datetime-local")]
-        [InlineData("datetime-local", null, "02/01/2000 03:04:05 -05:00", "datetime-local")]
-        [InlineData("DateTimeOffset", "{0:o}", "2000-01-02T03:04:05.0600000-05:00", "text")]
-        [InlineData("time", "{0:t}", "03:04", "time")]
         [ReplaceCulture]
         public void Editor_FindsCorrectDateOrTimeTemplate_NotRfc3339(
             string dataTypeName,
@@ -939,14 +976,32 @@ Environment.NewLine;
             Assert.Equal(expectedInput, HtmlContentUtilities.HtmlContentToString(result));
         }
 
+        public static TheoryData<string, string, string, string> Editor_FindsCorrectDateOrTimeTemplate_ForDateTimeData
+        {
+            get
+            {
+                AppContext.TryGetSwitch(TemplateRenderer.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+                var expectedZ = enabled ? string.Empty : "Z";
+                return new TheoryData<string, string, string, string>
+                {
+                    { null, null, "2000-01-02T03:04:05.060", "datetime-local" },
+                    { "date", "{0:d}", "2000-01-02", "date" },
+                    { "datetime", null, "2000-01-02T03:04:05.060", "datetime-local" },
+                    { "datetime-local", null, "2000-01-02T03:04:05.060", "datetime-local" },
+                    {
+                        "DateTimeOffset",
+                        "{0:o}",
+                        $"2000-01-02T03:04:05.060{expectedZ}",
+                        enabled ? "datetime-local" : "text"
+                    },
+                    { "time", "{0:t}", "03:04:05.060", "time" },
+                };
+            }
+        }
+
         // Html5DateRenderingMode.Rfc3339 is enabled by default.
         [Theory]
-        [InlineData(null, null, "2000-01-02T03:04:05.060", "datetime-local")]
+        [MemberData(nameof(Editor_FindsCorrectDateOrTimeTemplate_ForDateTimeData))]
-        [InlineData("date", "{0:d}", "2000-01-02", "date")]
-        [InlineData("datetime", null, "2000-01-02T03:04:05.060", "datetime-local")]
-        [InlineData("datetime-local", null, "2000-01-02T03:04:05.060", "datetime-local")]
-        [InlineData("DateTimeOffset", "{0:o}", "2000-01-02T03:04:05.060Z", "text")]
-        [InlineData("time", "{0:t}", "03:04:05.060", "time")]
         public void Editor_FindsCorrectDateOrTimeTemplate_ForDateTime(
             string dataTypeName,
             string editFormatString,
@@ -999,14 +1054,26 @@ Environment.NewLine;
             Assert.Equal(expectedInput, HtmlContentUtilities.HtmlContentToString(result));
         }
 
+        public static TheoryData<string, string, string, string> Editor_FindsCorrectDateOrTimeTemplate_ForDateTimeNotRfc3339Data
+        {
+            get
+            {
+                AppContext.TryGetSwitch(TemplateRenderer.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+                return new TheoryData<string, string, string, string>
+                {
+                    { null, null, "02/01/2000 03:04:05", "datetime-local" },
+                    { "date", "{0:d}", "02/01/2000", "date" },
+                    { "datetime", null, "02/01/2000 03:04:05", "datetime-local" },
+                    { "datetime-local", null, "02/01/2000 03:04:05", "datetime-local" },
+                    { "DateTimeOffset", "{0:o}", "2000-01-02T03:04:05.0600000Z", enabled ? "datetime-local" : "text" },
+                    { "time", "{0:t}", "03:04", "time" },
+                };
+            }
+        }
+
         // Html5DateRenderingMode.Rfc3339 can be disabled.
         [Theory]
-        [InlineData(null, null, "02/01/2000 03:04:05", "datetime-local")]
+        [MemberData(nameof(Editor_FindsCorrectDateOrTimeTemplate_ForDateTimeNotRfc3339Data))]
-        [InlineData("date", "{0:d}", "02/01/2000", "date")]
-        [InlineData("datetime", null, "02/01/2000 03:04:05", "datetime-local")]
-        [InlineData("datetime-local", null, "02/01/2000 03:04:05", "datetime-local")]
-        [InlineData("DateTimeOffset", "{0:o}", "2000-01-02T03:04:05.0600000Z", "text")]
-        [InlineData("time", "{0:t}", "03:04", "time")]
         [ReplaceCulture]
         public void Editor_FindsCorrectDateOrTimeTemplate_ForDateTimeNotRfc3339(
             string dataTypeName,
@@ -1062,17 +1129,29 @@ Environment.NewLine;
             Assert.Equal(expectedInput, HtmlContentUtilities.HtmlContentToString(result));
         }
 
+        public static TheoryData<string, Html5DateRenderingMode, string> Editor_AppliesNonDefaultEditFormatData
+        {
+            get
+            {
+                AppContext.TryGetSwitch(TemplateRenderer.UseDateTimeLocalTypeForDateTimeOffsetSwitch, out var enabled);
+                return new TheoryData<string, Html5DateRenderingMode, string>
+                {
+                    { null, Html5DateRenderingMode.CurrentCulture, enabled ? "datetime-local" : "text" },
+                    { null, Html5DateRenderingMode.Rfc3339, enabled ? "datetime-local" : "text" },
+                    { "date", Html5DateRenderingMode.CurrentCulture, "date" },
+                    { "date", Html5DateRenderingMode.Rfc3339, "date" },
+                    { "datetime", Html5DateRenderingMode.CurrentCulture, "datetime-local" },
+                    { "datetime", Html5DateRenderingMode.Rfc3339, "datetime-local" },
+                    { "datetime-local", Html5DateRenderingMode.CurrentCulture, "datetime-local" },
+                    { "datetime-local", Html5DateRenderingMode.Rfc3339, "datetime-local" },
+                    { "time", Html5DateRenderingMode.CurrentCulture, "time" },
+                    { "time", Html5DateRenderingMode.Rfc3339, "time" },
+                };
+            }
+        }
+
         [Theory]
-        [InlineData(null, Html5DateRenderingMode.CurrentCulture, "text")]
+        [MemberData(nameof(Editor_AppliesNonDefaultEditFormatData))]
-        [InlineData(null, Html5DateRenderingMode.Rfc3339, "text")]
-        [InlineData("date", Html5DateRenderingMode.CurrentCulture, "date")]
-        [InlineData("date", Html5DateRenderingMode.Rfc3339, "date")]
-        [InlineData("datetime", Html5DateRenderingMode.CurrentCulture, "datetime-local")]
-        [InlineData("datetime", Html5DateRenderingMode.Rfc3339, "datetime-local")]
-        [InlineData("datetime-local", Html5DateRenderingMode.CurrentCulture, "datetime-local")]
-        [InlineData("datetime-local", Html5DateRenderingMode.Rfc3339, "datetime-local")]
-        [InlineData("time", Html5DateRenderingMode.CurrentCulture, "time")]
-        [InlineData("time", Html5DateRenderingMode.Rfc3339, "time")]
         public void Editor_AppliesNonDefaultEditFormat(string dataTypeName, Html5DateRenderingMode renderingMode, string expectedType)
         {
             // Arrange