Use the correct time zone offsets

Author: mattjohnsonpint

src/System.Runtime.Serialization.Json/tests/DataContractJsonSerializer.cs

@@ -89,7 +89,7 @@ public static void DCJS_ByteAsRoot()
     [Fact]
     public static void DCJS_DateTimeAsRoot()
     {
-        var offsetMinutes = (int)TimeZoneInfo.Local.BaseUtcOffset.TotalMinutes;
+        var offsetMinutes = (int)TimeZoneInfo.Local.GetUtcOffset(new DateTime(2013, 1, 2)).TotalMinutes;
         var timeZoneString = string.Format("{0:+;-}{1}", offsetMinutes, new TimeSpan(0, offsetMinutes, 0).ToString(@"hhmm"));
         Assert.StrictEqual(SerializeAndDeserialize<DateTime>(new DateTime(2013, 1, 2).AddMinutes(offsetMinutes), string.Format("\"\\/Date(1357084800000{0})\\/\"", timeZoneString)), new DateTime(2013, 1, 2).AddMinutes(offsetMinutes));
         Assert.StrictEqual(SerializeAndDeserialize<DateTime>(new DateTime(2013, 1, 2, 3, 4, 5, 6, DateTimeKind.Local).AddMinutes(offsetMinutes), string.Format("\"\\/Date(1357095845006{0})\\/\"", timeZoneString)), new DateTime(2013, 1, 2, 3, 4, 5, 6, DateTimeKind.Local).AddMinutes(offsetMinutes));
@@ -997,7 +997,7 @@ public static void DCJS_JaggedArrayAsRoot()
         Assert.Equal(jaggedStringArray[1], actualJaggedStringArray[1]);
         Assert.Equal(jaggedStringArray[2], actualJaggedStringArray[2]);
 
-        var offsetMinutes = (int)TimeZoneInfo.Local.BaseUtcOffset.TotalMinutes;
+        var offsetMinutes = (int)TimeZoneInfo.Local.GetUtcOffset(new DateTime(2013, 1, 2)).TotalMinutes;
         var timeZoneString = string.Format("{0:+;-}{1}", offsetMinutes, new TimeSpan(0, offsetMinutes, 0).ToString(@"hhmm"));
         object[] objectArray = new object[] { 1, 1.0F, 1.0, "string", Guid.Parse("2054fd3e-e118-476a-9962-1a882be51860"), new DateTime(2013, 1, 2).AddMinutes(offsetMinutes) };
         var actualObjectArray = SerializeAndDeserialize<object[]>(objectArray, string.Format("[1,1,1,\"string\",\"2054fd3e-e118-476a-9962-1a882be51860\",\"\\/Date(1357084800000{0})\\/\"]", timeZoneString));

src/System.Runtime.Serialization.Xml/tests/DataContractSerializer.cs

@@ -20,7 +20,7 @@ public static class DataContractSerializerTests
     [Fact]
     public static void DCS_DateTimeOffsetAsRoot()
     {
-        var offsetMinutes = TimeZoneInfo.Local.BaseUtcOffset.TotalMinutes;
+        var offsetMinutes = TimeZoneInfo.Local.GetUtcOffset(new DateTime(2013, 1, 2)).TotalMinutes;
         var objs = new DateTimeOffset[]
         {
             // Adding offsetMinutes so the DateTime component in serialized strings are time-zone independent
@@ -87,7 +87,7 @@ public static void DCS_ByteAsRoot()
     [Fact]
     public static void DCS_DateTimeAsRoot()
     {
-        var offsetMinutes = (int)TimeZoneInfo.Local.BaseUtcOffset.TotalMinutes;
+        var offsetMinutes = (int)TimeZoneInfo.Local.GetUtcOffset(new DateTime(2013, 1, 2)).TotalMinutes;
         Assert.StrictEqual(SerializeAndDeserialize<DateTime>(new DateTime(2013, 1, 2), "<dateTime xmlns=\"http://schemas.microsoft.com/2003/10/Serialization/\">2013-01-02T00:00:00</dateTime>"), new DateTime(2013, 1, 2));
         Assert.StrictEqual(SerializeAndDeserialize<DateTime>(new DateTime(2013, 1, 2, 3, 4, 5, 6, DateTimeKind.Local), string.Format("<dateTime xmlns=\"http://schemas.microsoft.com/2003/10/Serialization/\">2013-01-02T03:04:05.006{0:+;-}{1}</dateTime>", offsetMinutes, new TimeSpan(0, offsetMinutes, 0).ToString(@"hh\:mm"))), new DateTime(2013, 1, 2, 3, 4, 5, 6, DateTimeKind.Local));
         Assert.StrictEqual(SerializeAndDeserialize<DateTime>(new DateTime(2013, 1, 2, 3, 4, 5, 6, DateTimeKind.Unspecified), "<dateTime xmlns=\"http://schemas.microsoft.com/2003/10/Serialization/\">2013-01-02T03:04:05.006</dateTime>"), new DateTime(2013, 1, 2, 3, 4, 5, 6, DateTimeKind.Unspecified));
@@ -1365,7 +1365,7 @@ public static void DCS_TypeWithDatetimeOffsetTypeProperty()
         Assert.StrictEqual(value.ModifiedTime, actual.ModifiedTime);
         Assert.StrictEqual(value.ModifiedTime.Offset, actual.ModifiedTime.Offset);
 
-        var offsetMinutes = TimeZoneInfo.Local.BaseUtcOffset.TotalMinutes;
+        var offsetMinutes = TimeZoneInfo.Local.GetUtcOffset(new DateTime(2013, 1, 2)).TotalMinutes;
         // Adding offsetMinutes to ModifiedTime property so the DateTime component in serialized strings are time-zone independent
         value = new TypeWithDateTimeOffsetTypeProperty() { ModifiedTime = new DateTimeOffset(new DateTime(2013, 1, 2, 3, 4, 5, 6).AddMinutes(offsetMinutes)) };
         actual = SerializeAndDeserialize(value, string.Format("<TypeWithDateTimeOffsetTypeProperty xmlns=\"http://schemas.datacontract.org/2004/07/SerializationTypes\" xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\"><ModifiedTime xmlns:a=\"http://schemas.datacontract.org/2004/07/System\"><a:DateTime>2013-01-02T03:04:05.006Z</a:DateTime><a:OffsetMinutes>{0}</a:OffsetMinutes></ModifiedTime></TypeWithDateTimeOffsetTypeProperty>", offsetMinutes));

src/System.Xml.XmlSerializer/tests/XmlSerializerTests.cs

@@ -54,7 +54,7 @@ public static void Xml_ByteAsRoot()
     [Fact]
     public static void Xml_DateTimeAsRoot()
     {
-        var offsetMinutes = (int)TimeZoneInfo.Local.BaseUtcOffset.TotalMinutes;
+        var offsetMinutes = (int)TimeZoneInfo.Local.GetUtcOffset(new DateTime(2013, 1, 2)).TotalMinutes;
         var timeZoneString = string.Format("{0:+;-}{1}", offsetMinutes, new TimeSpan(0, offsetMinutes, 0).ToString(@"hh\:mm"));
         Assert.StrictEqual(SerializeAndDeserialize<DateTime>(new DateTime(2013, 1, 2), "<?xml version=\"1.0\"?>" + Environment.NewLine + "<dateTime>2013-01-02T00:00:00</dateTime>"), new DateTime(2013, 1, 2));
         Assert.StrictEqual(SerializeAndDeserialize<DateTime>(new DateTime(2013, 1, 2, 3, 4, 5, 6, DateTimeKind.Local), string.Format("<?xml version=\"1.0\"?>" + Environment.NewLine + "<dateTime>2013-01-02T03:04:05.006{0}</dateTime>", timeZoneString)), new DateTime(2013, 1, 2, 3, 4, 5, 6, DateTimeKind.Local));