diff --git a/src/ServiceStack.Text/Common/DateTimeSerializer.cs b/src/ServiceStack.Text/Common/DateTimeSerializer.cs
index 05cae8b37..fd19170a0 100644
--- a/src/ServiceStack.Text/Common/DateTimeSerializer.cs
+++ b/src/ServiceStack.Text/Common/DateTimeSerializer.cs
@@ -56,7 +56,7 @@ public static DateTime ParseShortestXsdDateTime(string dateTimeStr)
 
 		public static string ToDateTimeString(DateTime dateTime)
 		{
-			return TimeZoneInfo.ConvertTimeToUtc(dateTime).ToString(XsdDateTimeFormat);
+			return dateTime.ToStableUniversalTime().ToString(XsdDateTimeFormat);
 		}
 
 		public static DateTime ParseDateTime(string dateTimeStr)
@@ -66,7 +66,7 @@ public static DateTime ParseDateTime(string dateTimeStr)
 
 		public static string ToXsdDateTimeString(DateTime dateTime)
 		{
-			return XmlConvert.ToString(TimeZoneInfo.ConvertTimeToUtc(dateTime), XmlDateTimeSerializationMode.Utc);
+			return XmlConvert.ToString(dateTime.ToStableUniversalTime(), XmlDateTimeSerializationMode.Utc);
 		}
 
 		public static DateTime ParseXsdDateTime(string dateTimeStr)
@@ -82,7 +82,7 @@ public static string ToShortestXsdDateTimeString(DateTime dateTime)
 				return dateTime.ToString(ShortDateTimeFormat);
 
 			if (timeOfDay.Milliseconds == 0)
-				return TimeZoneInfo.ConvertTimeToUtc(dateTime).ToString(XsdDateTimeFormatSeconds);
+				return dateTime.ToStableUniversalTime().ToString(XsdDateTimeFormatSeconds);
 
 			return ToXsdDateTimeString(dateTime);
 		}
diff --git a/src/ServiceStack.Text/DateTimeExtensions.cs b/src/ServiceStack.Text/DateTimeExtensions.cs
index 3f01db553..9cd41eb97 100644
--- a/src/ServiceStack.Text/DateTimeExtensions.cs
+++ b/src/ServiceStack.Text/DateTimeExtensions.cs
@@ -26,7 +26,7 @@ public static class DateTimeExtensions
 
 		public static long ToUnixTime(this DateTime dateTime)
 		{
-			return (TimeZoneInfo.ConvertTimeToUtc(dateTime).Ticks - UnixEpoch) / TimeSpan.TicksPerSecond;
+			return (dateTime.ToStableUniversalTime().Ticks - UnixEpoch) / TimeSpan.TicksPerSecond;
 		}
 
 		public static DateTime FromUnixTime(this double unixTime)
@@ -36,7 +36,7 @@ public static DateTime FromUnixTime(this double unixTime)
 
 		public static long ToUnixTimeMs(this DateTime dateTime)
 		{
-			return (TimeZoneInfo.ConvertTimeToUtc(dateTime).Ticks - UnixEpoch) / TimeSpan.TicksPerMillisecond;
+			return (dateTime.ToStableUniversalTime().Ticks - UnixEpoch) / TimeSpan.TicksPerMillisecond;
 		}
 
 		public static DateTime FromUnixTimeMs(this double msSince1970)
@@ -99,7 +99,7 @@ public static DateTime FromShortestXsdDateTimeString(this string xsdDateTime)
 
 		public static bool IsEqualToTheSecond(this DateTime dateTime, DateTime otherDateTime)
 		{
-			return TimeZoneInfo.ConvertTimeToUtc(dateTime).RoundToSecond().Equals(TimeZoneInfo.ConvertTimeToUtc(otherDateTime).RoundToSecond());
+			return dateTime.ToStableUniversalTime().RoundToSecond().Equals(otherDateTime.ToStableUniversalTime().RoundToSecond());
 		}
 
 		public static string ToTimeOffsetString(this TimeSpan offset, bool includeColon = false)
@@ -120,5 +120,17 @@ public static TimeSpan FromTimeOffsetString(this string offsetString)
 
 			return TimeSpan.Parse(offsetString);
 		}
+
+		public static DateTime ToStableUniversalTime(this DateTime dateTime)
+		{
+#if SILVERLIGHT
+			// Silverlight 3, 4 and 5 all work ok with DateTime.ToUniversalTime, but have no TimeZoneInfo.ConverTimeToUtc implementation.
+			return dateTime.ToUniversalTime();
+#else
+			// .Net 2.0 - 3.5 has an issue with DateTime.ToUniversalTime, but works ok with TimeZoneInfo.ConvertTimeToUtc.
+			// .Net 4.0+ does this under the hood anyway.
+			return TimeZoneInfo.ConvertTimeToUtc(dateTime);
+#endif
+		}
 	}
 }
\ No newline at end of file
diff --git a/tests/ServiceStack.Text.Tests/Utils/DateTimeSerializerTests.cs b/tests/ServiceStack.Text.Tests/Utils/DateTimeSerializerTests.cs
index c67965882..7a5cbd71a 100644
--- a/tests/ServiceStack.Text.Tests/Utils/DateTimeSerializerTests.cs
+++ b/tests/ServiceStack.Text.Tests/Utils/DateTimeSerializerTests.cs
@@ -40,12 +40,12 @@ public void ToShortestXsdDateTimeString_works()
 			const string shortDateString = "1979-05-09";
 
 			var shortDateTime = new DateTime(1979, 5, 9, 0, 0, 1, DateTimeKind.Utc);
-			var shortDateTimeString = shortDateTime.Equals(TimeZoneInfo.ConvertTimeToUtc(shortDateTime))
+			var shortDateTimeString = shortDateTime.Equals(shortDateTime.ToStableUniversalTime())
               	? "1979-05-09T00:00:01Z"
               	: "1979-05-08T23:00:01Z";
 
 			var longDateTime = new DateTime(1979, 5, 9, 0, 0, 0, 1, DateTimeKind.Utc);
-			var longDateTimeString = longDateTime.Equals(TimeZoneInfo.ConvertTimeToUtc(longDateTime))
+			var longDateTimeString = longDateTime.Equals(longDateTime.ToStableUniversalTime())
          		? "1979-05-09T00:00:00.001Z"
          		: "1979-05-08T23:00:00.001Z";
 
@@ -58,7 +58,7 @@ public void ToShortestXsdDateTimeString_works()
 		public void Utc_Local_Equals()
 		{
 			var now = DateTime.Now;
-			var utcNow = TimeZoneInfo.ConvertTimeToUtc(now);
+			var utcNow = now.ToStableUniversalTime();
 
 			Assert.That(now.Ticks, Is.EqualTo(utcNow.Ticks), "Ticks are different");
 			Assert.That(now, Is.EqualTo(utcNow), "DateTimes are different");
@@ -122,7 +122,7 @@ public void AssertDateIsEqual(int whichDate)
 
 			//Don't test short dates without time to UTC as you lose precision
 			var shortDateStr = dateTime.ToString(DateTimeSerializer.ShortDateTimeFormat);
-			var shortDateTimeStr = TimeZoneInfo.ConvertTimeToUtc(dateTime).ToString(DateTimeSerializer.XsdDateTimeFormatSeconds);
+			var shortDateTimeStr = dateTime.ToStableUniversalTime().ToString(DateTimeSerializer.XsdDateTimeFormatSeconds);
 			var longDateTimeStr = DateTimeSerializer.ToXsdDateTimeString(dateTime);
 			var shortestDateStr = DateTimeSerializer.ToShortestXsdDateTimeString(dateTime);
 
@@ -135,14 +135,14 @@ public void AssertDateIsEqual(int whichDate)
 
 			Assert.That(shortDate, Is.EqualTo(dateTime.Date));
 
-			var shortDateTimeUtc = TimeZoneInfo.ConvertTimeToUtc(shortDateTime);
+			var shortDateTimeUtc = shortDateTime.ToStableUniversalTime();
 			Assert.That(shortDateTimeUtc, Is.EqualTo(
 				new DateTime(
 					shortDateTimeUtc.Year, shortDateTimeUtc.Month, shortDateTimeUtc.Day,
 					shortDateTimeUtc.Hour, shortDateTimeUtc.Minute, shortDateTimeUtc.Second,
 					shortDateTimeUtc.Millisecond, DateTimeKind.Utc)));
 
-			Assert.That(TimeZoneInfo.ConvertTimeToUtc(longDateTime), Is.EqualTo(TimeZoneInfo.ConvertTimeToUtc(dateTime)));
+			Assert.That(longDateTime.ToStableUniversalTime(), Is.EqualTo(dateTime.ToStableUniversalTime()));
 
 			var toDateTime = DateTimeSerializer.ParseShortestXsdDateTime(shortestDateStr);
 			AssertDatesAreEqual(toDateTime, dateTime, "shortestDate");
@@ -158,7 +158,7 @@ public void AssertDateIsEqual(int whichDate)
 
         private void AssertDatesAreEqual(DateTime toDateTime, DateTime dateTime, string which)
         {
-			Assert.That(TimeZoneInfo.ConvertTimeToUtc(toDateTime).RoundToMs(), Is.EqualTo(TimeZoneInfo.ConvertTimeToUtc(dateTime).RoundToMs()), which);
+			Assert.That(toDateTime.ToStableUniversalTime().RoundToMs(), Is.EqualTo(dateTime.ToStableUniversalTime().RoundToMs()), which);
         }
 	}
 }
\ No newline at end of file