Added 15 unit tests to cover time zone conversion, and fixed a bug that the new tests revealed.

src/Orchard.Tests/Localization/DateTimePartsTests.cs

@@ -2,7 +2,7 @@
 using NUnit.Framework;
 using Orchard.Localization.Models;
 
-namespace Orchard.Framework.Tests.Localization {
+namespace Orchard.Tests.Localization {
 
     [TestFixture]
     public class DateTimePartsTests {

src/Orchard.Tests/Localization/DefaultDateFormatterTests.cs

@@ -7,12 +7,11 @@ using System.Linq;
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using Autofac;
-using Moq;
 using NUnit.Framework;
 using Orchard.Localization.Models;
 using Orchard.Localization.Services;
 
-namespace Orchard.Framework.Tests.Localization {
+namespace Orchard.Tests.Localization {
 
     [TestFixture]
     public class DefaultDateFormatterTests {
@@ -36,7 +35,7 @@ namespace Orchard.Framework.Tests.Localization {
 
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
-                var container = InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
+                var container = TestHelpers.InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
                 var formats = container.Resolve<IDateTimeFormatProvider>();
                 var target = container.Resolve<IDateFormatter>();
 
@@ -85,7 +84,7 @@ namespace Orchard.Framework.Tests.Localization {
 
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
-                var container = InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
+                var container = TestHelpers.InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
                 var formats = container.Resolve<IDateTimeFormatProvider>();
                 var target = container.Resolve<IDateFormatter>();
 
@@ -135,7 +134,7 @@ namespace Orchard.Framework.Tests.Localization {
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
                 foreach (var timeZone in new[] { TimeZoneInfo.Utc, TimeZoneInfo.Local, TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time"), TimeZoneInfo.FindSystemTimeZoneById("Iran Standard Time") }) { // Enough time zones to get good coverage: UTC, local, one negative offset and one positive offset.
-                    var container = InitializeContainer(culture.Name, "GregorianCalendar", timeZone);
+                    var container = TestHelpers.InitializeContainer(culture.Name, "GregorianCalendar", timeZone);
                     var formats = container.Resolve<IDateTimeFormatProvider>();
                     var target = container.Resolve<IDateFormatter>();
 
@@ -192,7 +191,7 @@ namespace Orchard.Framework.Tests.Localization {
         [Description("Date/time parsing throws a FormatException for unparsable date/time strings.")]
         [ExpectedException(typeof(FormatException))]
         public void ParseDateTimeTest04() {
-            var container = InitializeContainer("en-US", null, TimeZoneInfo.Utc);
+            var container = TestHelpers.InitializeContainer("en-US", null, TimeZoneInfo.Utc);
             var target = container.Resolve<IDateFormatter>();
             target.ParseDateTime("BlaBlaBla");
         }
@@ -211,7 +210,7 @@ namespace Orchard.Framework.Tests.Localization {
 
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
-                var container = InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
+                var container = TestHelpers.InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
                 var formats = container.Resolve<IDateTimeFormatProvider>();
                 var target = container.Resolve<IDateFormatter>();
 
@@ -250,7 +249,7 @@ namespace Orchard.Framework.Tests.Localization {
         [Description("Date parsing throws a FormatException for unparsable date strings.")]
         [ExpectedException(typeof(FormatException))]
         public void ParseDateTest02() {
-            var container = InitializeContainer("en-US", null, TimeZoneInfo.Utc);
+            var container = TestHelpers.InitializeContainer("en-US", null, TimeZoneInfo.Utc);
             var target = container.Resolve<IDateFormatter>();
             target.ParseDate("BlaBlaBla");
         }
@@ -269,7 +268,7 @@ namespace Orchard.Framework.Tests.Localization {
 
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
-                var container = InitializeContainer(culture.Name, null, TimeZoneInfo.Utc);
+                var container = TestHelpers.InitializeContainer(culture.Name, null, TimeZoneInfo.Utc);
                 var formats = container.Resolve<IDateTimeFormatProvider>();
                 var target = container.Resolve<IDateFormatter>();
 
@@ -304,7 +303,7 @@ namespace Orchard.Framework.Tests.Localization {
         [Description("Time parsing throws a FormatException for unparsable time strings.")]
         [ExpectedException(typeof(FormatException))]
         public void ParseTimeTest02() {
-            var container = InitializeContainer("en-US", null, TimeZoneInfo.Utc);
+            var container = TestHelpers.InitializeContainer("en-US", null, TimeZoneInfo.Utc);
             var target = container.Resolve<IDateFormatter>();
             target.ParseTime("BlaBlaBla");
         }
@@ -323,7 +322,7 @@ namespace Orchard.Framework.Tests.Localization {
 
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
-                var container = InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
+                var container = TestHelpers.InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
                 var formats = container.Resolve<IDateTimeFormatProvider>();
                 var target = container.Resolve<IDateFormatter>();
 
@@ -386,7 +385,7 @@ namespace Orchard.Framework.Tests.Localization {
 
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
-                var container = InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
+                var container = TestHelpers.InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
                 var formats = container.Resolve<IDateTimeFormatProvider>();
                 var target = container.Resolve<IDateFormatter>();
 
@@ -450,7 +449,7 @@ namespace Orchard.Framework.Tests.Localization {
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
                 foreach (var timeZone in new[] { TimeZoneInfo.Utc, TimeZoneInfo.Local, TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time"), TimeZoneInfo.FindSystemTimeZoneById("Iran Standard Time") }) { // Enough time zones to get good coverage: UTC, local, one negative offset and one positive offset.
-                    var container = InitializeContainer(culture.Name, "GregorianCalendar", timeZone);
+                    var container = TestHelpers.InitializeContainer(culture.Name, "GregorianCalendar", timeZone);
                     var formats = container.Resolve<IDateTimeFormatProvider>();
                     var target = container.Resolve<IDateFormatter>();
 
@@ -540,7 +539,7 @@ namespace Orchard.Framework.Tests.Localization {
 
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
-                var container = InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
+                var container = TestHelpers.InitializeContainer(culture.Name, "GregorianCalendar", TimeZoneInfo.Utc);
                 var formats = container.Resolve<IDateTimeFormatProvider>();
                 var target = container.Resolve<IDateFormatter>();
 
@@ -603,7 +602,7 @@ namespace Orchard.Framework.Tests.Localization {
 
             var allCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);
             Parallel.ForEach(allCultures, options, culture => { // All cultures on the machine.
-                var container = InitializeContainer(culture.Name, null, TimeZoneInfo.Utc);
+                var container = TestHelpers.InitializeContainer(culture.Name, null, TimeZoneInfo.Utc);
                 var formats = container.Resolve<IDateTimeFormatProvider>();
                 var target = container.Resolve<IDateFormatter>();
 
@@ -682,73 +681,5 @@ namespace Orchard.Framework.Tests.Localization {
                 expectedOffset
             );
         }
-
-        private IContainer InitializeContainer(string cultureName, string calendarName, TimeZoneInfo timeZone) {
-            var builder = new ContainerBuilder();
-            builder.RegisterInstance<WorkContext>(new StubWorkContext(cultureName, calendarName, timeZone));
-            builder.RegisterType<StubWorkContextAccessor>().As<IWorkContextAccessor>();
-            builder.RegisterType<CultureDateTimeFormatProvider>().As<IDateTimeFormatProvider>();
-            builder.RegisterType<DefaultDateFormatter>().As<IDateFormatter>();
-            builder.RegisterInstance(new Mock<ICalendarSelector>().Object);
-            builder.RegisterType<DefaultCalendarManager>().As<ICalendarManager>();
-            return builder.Build();
-        }
-
-        private class StubWorkContext : WorkContext {
-
-            private string _cultureName;
-            private string _calendarName;
-            private TimeZoneInfo _timeZone;
-
-            public StubWorkContext(string cultureName, string calendarName, TimeZoneInfo timeZone) {
-                _cultureName = cultureName;
-                _calendarName = calendarName;
-                _timeZone = timeZone;
-            }
-
-            public override T Resolve<T>() {
-                throw new NotImplementedException();
-            }
-
-            public override bool TryResolve<T>(out T service) {
-                throw new NotImplementedException();
-            }
-
-            public override T GetState<T>(string name) {
-                if (name == "CurrentCulture") return (T)((object)_cultureName);
-                if (name == "CurrentCalendar") return (T)((object)_calendarName);
-                if (name == "CurrentTimeZone") return (T)((object)_timeZone);
-                throw new NotImplementedException(String.Format("Property '{0}' is not implemented.", name));
-            }
-
-            public override void SetState<T>(string name, T value) {
-                throw new NotImplementedException();
-            }
-        }
-
-        private class StubWorkContextAccessor : IWorkContextAccessor {
-
-            private WorkContext _workContext;
-
-            public StubWorkContextAccessor(WorkContext workContext) {
-                _workContext = workContext;
-            }
-
-            public WorkContext GetContext(System.Web.HttpContextBase httpContext) {
-                throw new NotImplementedException();
-            }
-
-            public IWorkContextScope CreateWorkContextScope(System.Web.HttpContextBase httpContext) {
-                throw new NotImplementedException();
-            }
-
-            public WorkContext GetContext() {
-                return _workContext;
-            }
-
-            public IWorkContextScope CreateWorkContextScope() {
-                throw new NotImplementedException();
-            }
-        }
     }
 }

src/Orchard.Tests/Localization/DefaultDateLocalizationServicesTests.cs

@@ -0,0 +1,219 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.Linq;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using Autofac;
+using NUnit.Framework;
+using Orchard.Localization.Models;
+using Orchard.Localization.Services;
+
+namespace Orchard.Tests.Localization {
+
+    [TestFixture]
+    public class DefaultDateLocalizationServicesTests {
+
+        [SetUp]
+        public void Init() {
+            //Regex.CacheSize = 1024;
+        }
+
+        [Test]
+        [Description("Date component is decremented by one day when converting to time zone with negative offset greater than time component.")]
+        public void ConvertToSiteTimeZoneTest01() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.LessThan(TimeSpan.FromHours(-3)));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeUtc = new DateTime(1998, 1, 15, 3, 0, 0, DateTimeKind.Utc);
+            var result = target.ConvertToSiteTimeZone(dateTimeUtc);
+            Assert.AreEqual(14, result.Day);
+        }
+
+        [Test]
+        [Description("Date component is incremented by one day when converting to time zone with positive offset greater than 24 hours minus time component.")]
+        public void ConvertToSiteTimeZoneTest02() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("India Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.GreaterThan(TimeSpan.FromHours(3)));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeUtc = new DateTime(1998, 1, 15, 21, 0, 0, DateTimeKind.Utc);
+            var result = target.ConvertToSiteTimeZone(dateTimeUtc);
+            Assert.AreEqual(16, result.Day);
+        }
+
+        [Test]
+        [Description("DateTime which is DateTimeKind.Utc is converted to DateTimeKind.Local with offset when target time zone is not UTC.")]
+        public void ConvertToSiteTimeZoneTest03() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Central European Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.Not.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeUtc = new DateTime(1998, 1, 15, 3, 0, 0, DateTimeKind.Utc);
+            var result = target.ConvertToSiteTimeZone(dateTimeUtc);
+            Assert.AreEqual(DateTimeKind.Local, result.Kind);
+            Assert.AreEqual(dateTimeUtc.Hour + timeZone.BaseUtcOffset.Hours, result.Hour);
+        }
+
+        [Test]
+        [Description("DateTime which is DateTimeKind.Utc is not converted when target time zone is UTC.")]
+        public void ConvertToSiteTimeZoneTest04() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("UTC");
+            Assert.That(timeZone.BaseUtcOffset, Is.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeUtc = new DateTime(1998, 1, 15, 3, 0, 0, DateTimeKind.Utc);
+            var result = target.ConvertToSiteTimeZone(dateTimeUtc);
+            Assert.AreEqual(DateTimeKind.Utc, result.Kind);
+            Assert.AreEqual(dateTimeUtc, result);
+        }
+
+        [Test]
+        [Description("DateTime which is DateTimeKind.Unspecified is converted to DateTimeKind.Local with offset when target time zone is not UTC.")]
+        public void ConvertToSiteTimeZoneTest05() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Central European Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.Not.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeUtc = new DateTime(1998, 1, 15, 3, 0, 0, DateTimeKind.Unspecified);
+            var result = target.ConvertToSiteTimeZone(dateTimeUtc);
+            Assert.AreEqual(DateTimeKind.Local, result.Kind);
+            Assert.AreEqual(dateTimeUtc.Hour + timeZone.BaseUtcOffset.Hours, result.Hour);
+        }
+
+        [Test]
+        [Description("DateTime which is DateTimeKind.Unspecified is converted to DateTimeKind.Utc with no offset when target time zone is UTC.")]
+        public void ConvertToSiteTimeZoneTest06() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("UTC");
+            Assert.That(timeZone.BaseUtcOffset, Is.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeUtc = new DateTime(1998, 1, 15, 3, 0, 0, DateTimeKind.Unspecified);
+            var result = target.ConvertToSiteTimeZone(dateTimeUtc);
+            Assert.AreEqual(DateTimeKind.Utc, result.Kind);
+            Assert.AreEqual(dateTimeUtc, result);
+        }
+
+        [Test]
+        [Description("DateTime which is already DateTimeKind.Local is never converted.")]
+        public void ConvertToSiteTimeZoneTest07() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.Not.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeUtc = new DateTime(1998, 1, 15, 3, 0, 0, DateTimeKind.Local);
+            var result = target.ConvertToSiteTimeZone(dateTimeUtc);
+            Assert.AreEqual(DateTimeKind.Local, result.Kind);
+            Assert.AreEqual(dateTimeUtc, result);
+        }
+
+        [Test]
+        [Description("Resulting DateTime is DateTimeKind.Local even when target time zone is not configured time zone of local computer.")]
+        public void ConvertToSiteTimeZoneTest08() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Central European Standard Time");
+            if (timeZone == TimeZoneInfo.Local) {
+                timeZone = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");
+            }
+            Assert.That(timeZone.BaseUtcOffset, Is.Not.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeUtc = new DateTime(1998, 1, 15, 3, 0, 0, DateTimeKind.Utc);
+            var result = target.ConvertToSiteTimeZone(dateTimeUtc);
+            Assert.AreEqual(DateTimeKind.Local, result.Kind);
+        }
+
+        [Test]
+        [Description("Date component is incremented by one day when converting from time zone with negative offset greater than 24 hours minus time component.")]
+        public void ConvertFromSiteTimeZoneTest01() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.LessThan(TimeSpan.FromHours(-3)));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeLocal = new DateTime(1998, 1, 15, 21, 0, 0, DateTimeKind.Local);
+            var result = target.ConvertFromSiteTimeZone(dateTimeLocal);
+            Assert.AreEqual(16, result.Day);
+        }
+
+        [Test]
+        [Description("Date component is decremented by one day when converting from time zone with positive offset greater than time component.")]
+        public void ConvertFromSiteTimeZoneTest02() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("India Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.GreaterThan(TimeSpan.FromHours(3)));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeLocal = new DateTime(1998, 1, 15, 3, 0, 0, DateTimeKind.Local);
+            var result = target.ConvertFromSiteTimeZone(dateTimeLocal);
+            Assert.AreEqual(14, result.Day);
+        }
+
+        [Test]
+        [Description("DateTime which is DateTimeKind.Local is converted to DateTimeKind.Utc with offset when target time zone is not UTC.")]
+        public void ConvertFromSiteTimeZoneTest03() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Central European Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.Not.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeLocal = new DateTime(1998, 1, 15, 21, 0, 0, DateTimeKind.Local);
+            var result = target.ConvertFromSiteTimeZone(dateTimeLocal);
+            Assert.AreEqual(DateTimeKind.Utc, result.Kind);
+            Assert.AreEqual(dateTimeLocal.Hour - timeZone.BaseUtcOffset.Hours, result.Hour);
+        }
+
+        [Test]
+        [Description("DateTime which is DateTimeKind.Local is converted to DateTimeKind.Utc with no offset when target time zone is UTC.")]
+        public void ConvertFromSiteTimeZoneTest04() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("UTC");
+            Assert.That(timeZone.BaseUtcOffset, Is.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeLocal = new DateTime(1998, 1, 15, 21, 0, 0, DateTimeKind.Local);
+            var result = target.ConvertFromSiteTimeZone(dateTimeLocal);
+            Assert.AreEqual(DateTimeKind.Utc, result.Kind);
+            Assert.AreEqual(dateTimeLocal.Hour, result.Hour);
+            Assert.AreEqual(dateTimeLocal.Minute, result.Minute);
+        }
+
+        [Test]
+        [Description("DateTime which is DateTimeKind.Unspecified is converted to DateTimeKind.Utc with offset when target time zone is not UTC.")]
+        public void ConvertFromSiteTimeZoneTest05() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Central European Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.Not.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeLocal = new DateTime(1998, 1, 15, 21, 0, 0, DateTimeKind.Unspecified);
+            var result = target.ConvertFromSiteTimeZone(dateTimeLocal);
+            Assert.AreEqual(DateTimeKind.Utc, result.Kind);
+            Assert.AreEqual(dateTimeLocal.Hour - timeZone.BaseUtcOffset.Hours, result.Hour);
+        }
+
+        [Test]
+        [Description("DateTime which is DateTimeKind.Unspecified is converted to DateTimeKind.Utc with no offset when target time zone is UTC.")]
+        public void ConvertFromSiteTimeZoneTest06() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("UTC");
+            Assert.That(timeZone.BaseUtcOffset, Is.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeLocal = new DateTime(1998, 1, 15, 21, 0, 0, DateTimeKind.Unspecified);
+            var result = target.ConvertFromSiteTimeZone(dateTimeLocal);
+            Assert.AreEqual(DateTimeKind.Utc, result.Kind);
+            Assert.AreEqual(dateTimeLocal.Hour, result.Hour);
+            Assert.AreEqual(dateTimeLocal.Minute, result.Minute);
+        }
+
+        [Test]
+        [Description("DateTime which is already DateTimeKind.Utc is never converted.")]
+        public void ConvertFromSiteTimeZoneTest07() {
+            var timeZone = TimeZoneInfo.FindSystemTimeZoneById("Central European Standard Time");
+            Assert.That(timeZone.BaseUtcOffset, Is.Not.EqualTo(TimeSpan.Zero));
+            var container = TestHelpers.InitializeContainer(null, null, timeZone);
+            var target = container.Resolve<IDateLocalizationServices>();
+            var dateTimeLocal = new DateTime(1998, 1, 15, 21, 0, 0, DateTimeKind.Utc);
+            var result = target.ConvertFromSiteTimeZone(dateTimeLocal);
+            Assert.AreEqual(DateTimeKind.Utc, result.Kind);
+            Assert.AreEqual(dateTimeLocal, result);
+        }
+    }
+}

src/Orchard.Tests/Localization/TestHelpers.cs

@@ -0,0 +1,85 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Autofac;
+using Moq;
+using Orchard.Localization.Services;
+using Orchard.Services;
+using Orchard.Tests.Stubs;
+
+namespace Orchard.Tests.Localization {
+
+    internal class TestHelpers {
+        public static IContainer InitializeContainer(string cultureName, string calendarName, TimeZoneInfo timeZone) {
+            var builder = new ContainerBuilder();
+            builder.RegisterType<StubClock>().As<IClock>();
+            builder.RegisterInstance<WorkContext>(new StubWorkContext(cultureName, calendarName, timeZone));
+            builder.RegisterType<StubWorkContextAccessor>().As<IWorkContextAccessor>();
+            builder.RegisterType<CultureDateTimeFormatProvider>().As<IDateTimeFormatProvider>();
+            builder.RegisterType<DefaultDateFormatter>().As<IDateFormatter>();
+            builder.RegisterInstance(new Mock<ICalendarSelector>().Object);
+            builder.RegisterType<DefaultCalendarManager>().As<ICalendarManager>();
+            builder.RegisterType<DefaultDateLocalizationServices>().As<IDateLocalizationServices>();
+            return builder.Build();
+        }
+    }
+
+    internal class StubWorkContext : WorkContext {
+
+        private string _cultureName;
+        private string _calendarName;
+        private TimeZoneInfo _timeZone;
+
+        public StubWorkContext(string cultureName, string calendarName, TimeZoneInfo timeZone) {
+            _cultureName = cultureName;
+            _calendarName = calendarName;
+            _timeZone = timeZone;
+        }
+
+        public override T Resolve<T>() {
+            throw new NotImplementedException();
+        }
+
+        public override bool TryResolve<T>(out T service) {
+            throw new NotImplementedException();
+        }
+
+        public override T GetState<T>(string name) {
+            if (name == "CurrentCulture") return (T)((object)_cultureName);
+            if (name == "CurrentCalendar") return (T)((object)_calendarName);
+            if (name == "CurrentTimeZone") return (T)((object)_timeZone);
+            throw new NotImplementedException(String.Format("Property '{0}' is not implemented.", name));
+        }
+
+        public override void SetState<T>(string name, T value) {
+            throw new NotImplementedException();
+        }
+    }
+
+    internal class StubWorkContextAccessor : IWorkContextAccessor {
+
+        private WorkContext _workContext;
+
+        public StubWorkContextAccessor(WorkContext workContext) {
+            _workContext = workContext;
+        }
+
+        public WorkContext GetContext(System.Web.HttpContextBase httpContext) {
+            throw new NotImplementedException();
+        }
+
+        public IWorkContextScope CreateWorkContextScope(System.Web.HttpContextBase httpContext) {
+            throw new NotImplementedException();
+        }
+
+        public WorkContext GetContext() {
+            return _workContext;
+        }
+
+        public IWorkContextScope CreateWorkContextScope() {
+            throw new NotImplementedException();
+        }
+    }
+}

src/Orchard.Tests/Orchard.Framework.Tests.csproj

@@ -260,7 +260,9 @@
     <Compile Include="FileSystems\VirtualPath\DefaultVirtualPathProviderTests.cs" />
     <Compile Include="Localization\CultureManagerTests.cs" />
     <Compile Include="Localization\DateTimePartsTests.cs" />
+    <Compile Include="Localization\DefaultDateLocalizationServicesTests.cs" />
     <Compile Include="Localization\DefaultDateFormatterTests.cs" />
+    <Compile Include="Localization\TestHelpers.cs" />
     <Compile Include="Logging\OrchardFileAppenderTests.cs" />
     <Compile Include="Messaging\MessagingChannelStub.cs" />
     <Compile Include="Mvc\Html\HtmlHelperExtensionsTests.cs" />

src/Orchard.Web/Modules/Orchard.Tokens/Providers/DateTokens.cs

@@ -81,7 +81,7 @@ namespace Orchard.Tokens.Providers {
             var time = _clock.UtcNow - dateTimeUtc.ToUniversalTime();
 
             if (time.TotalDays > 7)
-                return _dateFormatter.FormatDateTime(DateTimeParts.FromDateTime(dateTimeUtc), T("'on' MMM d yyyy 'at' h:mm tt").ToString());
+                return _dateLocalizationServices.ConvertToLocalizedString(dateTimeUtc, T("'on' MMM d yyyy 'at' h:mm tt").Text);
             if (time.TotalHours > 24)
                 return T.Plural("1 day ago", "{0} days ago", time.Days).ToString();
             if (time.TotalMinutes > 60)

src/Orchard/Localization/Services/DefaultDateLocalizationServices.cs

@@ -28,14 +28,26 @@ namespace Orchard.Localization.Services {
             _calendarManager = calendarManager;
         }
 
-        public virtual DateTime ConvertToSiteTimeZone(DateTime date) {
-            var workContext = _workContextAccessor.GetContext();
-            return TimeZoneInfo.ConvertTimeFromUtc(date, workContext.CurrentTimeZone);
+        public virtual DateTime ConvertToSiteTimeZone(DateTime dateUtc) {
+            if (dateUtc.Kind == DateTimeKind.Local) {
+                return dateUtc;
+            }
+            if (CurrentTimeZone == TimeZoneInfo.Utc) {
+                if (dateUtc.Kind == DateTimeKind.Unspecified) {
+                    return new DateTime(dateUtc.Ticks, DateTimeKind.Utc);
+                }
+                return dateUtc;
+            }
+            var dateLocal = dateUtc + CurrentTimeZone.BaseUtcOffset;
+            return new DateTime(dateLocal.Ticks, DateTimeKind.Local);
         }
 
-        public virtual DateTime ConvertFromSiteTimeZone(DateTime date) {
-            var workContext = _workContextAccessor.GetContext();
-            return TimeZoneInfo.ConvertTimeToUtc(date, workContext.CurrentTimeZone);
+        public virtual DateTime ConvertFromSiteTimeZone(DateTime dateLocal) {
+            if (dateLocal.Kind == DateTimeKind.Utc) {
+                return dateLocal;
+            } 
+            var dateUtc = dateLocal - CurrentTimeZone.BaseUtcOffset;
+            return new DateTime(dateUtc.Ticks, DateTimeKind.Utc);
         }
 
         public virtual DateTimeParts ConvertToSiteCalendar(DateTime date, TimeSpan offset) {
@@ -48,12 +60,21 @@ namespace Orchard.Localization.Services {
                 calendar.GetMinute(date),
                 calendar.GetSecond(date),
                 Convert.ToInt32(calendar.GetMilliseconds(date)),
-                DateTimeKind.Utc,
+                date.Kind,
                 offset);
         }
 
         public virtual DateTime ConvertFromSiteCalendar(DateTimeParts parts) {
-            return CurrentCalendar.ToDateTime(parts.Date.Year, parts.Date.Month, parts.Date.Day, parts.Time.Hour, parts.Time.Minute, parts.Time.Second, parts.Time.Millisecond);
+            return new DateTime(
+                parts.Date.Year,
+                parts.Date.Month, 
+                parts.Date.Day,
+                parts.Time.Hour, 
+                parts.Time.Minute,
+                parts.Time.Second, 
+                parts.Time.Millisecond,
+                CurrentCalendar,
+                parts.Time.Kind);
         }
 
         public string ConvertToLocalizedDateString(DateTime date, DateLocalizationOptions options = null) {
@@ -85,13 +106,11 @@ namespace Orchard.Localization.Services {
                 // * Time zone conversion cannot wrap DateTime.MinValue around to the previous day, resulting in undefined result.
                 // Therefore we convert the date to today's date before the conversion, and back to DateTime.MinValue after.
                 var now = _clock.UtcNow;
-
                 dateValue = new DateTime(now.Year, now.Month, now.Day, dateValue.Hour, dateValue.Minute, dateValue.Second, dateValue.Millisecond, dateValue.Kind);
                 dateValue = ConvertToSiteTimeZone(dateValue);
                 dateValue = new DateTime(DateTime.MinValue.Year, DateTime.MinValue.Month, DateTime.MinValue.Day, dateValue.Hour, dateValue.Minute, dateValue.Second, dateValue.Millisecond, dateValue.Kind);
 
-                var workContext = _workContextAccessor.GetContext();
-                offset = workContext.CurrentTimeZone.BaseUtcOffset;
+                offset = CurrentTimeZone.BaseUtcOffset;
             }
 
             var parts = DateTimeParts.FromDateTime(dateValue, offset);
@@ -125,8 +144,7 @@ namespace Orchard.Localization.Services {
 
             if (options.EnableTimeZoneConversion) {
                 dateValue = ConvertToSiteTimeZone(dateValue);
-                var workContext = _workContextAccessor.GetContext();
-                offset = workContext.CurrentTimeZone.BaseUtcOffset;
+                offset = CurrentTimeZone.BaseUtcOffset;
             }
 
             var parts = DateTimeParts.FromDateTime(dateValue, offset);
@@ -226,6 +244,13 @@ namespace Orchard.Localization.Services {
             }
         }
 
+        protected virtual TimeZoneInfo CurrentTimeZone {
+            get {
+                var workContext = _workContextAccessor.GetContext();
+                return workContext.CurrentTimeZone;
+            }
+        }
+
         protected virtual DateTime? ToNullable(DateTime date) {
             return date == DateTime.MinValue ? new DateTime?() : new DateTime?(date);
         }