Add fallback for TimeZoneInfo.Local for Mono on Windows

Author: mythz

src/ServiceStack.Text/Common/DateTimeSerializer.cs

@@ -445,7 +445,20 @@ public static DateTime ParseWcfJsonDate(string wcfJsonDate)
             return new DateTimeOffset(date, offset).DateTime;
         }
 
-        private static TimeZoneInfo LocalTimeZone = TimeZoneInfo.Local;
+        public static TimeZoneInfo GetLocalTimeZoneInfo()
+        {
+            try
+            {
+                return TimeZoneInfo.Local;
+            }
+            catch (Exception)
+            {
+                return TimeZoneInfo.Utc; //Fallback for Mono on Windows.
+            }
+        }
+
+        internal static TimeZoneInfo LocalTimeZone = GetLocalTimeZoneInfo();
+
         public static void WriteWcfJsonDate(TextWriter writer, DateTime dateTime)
         {
             if (JsConfig.AssumeUtc && dateTime.Kind == DateTimeKind.Unspecified)

src/ServiceStack.Text/DateTimeExtensions.cs

@@ -46,7 +46,6 @@ public static long ToUnixTimeMsAlt(this DateTime dateTime)
             return (dateTime.ToStableUniversalTime().Ticks - UnixEpoch) / TimeSpan.TicksPerMillisecond;
         }
 
-        private static TimeZoneInfo LocalTimeZone = TimeZoneInfo.Local;
         public static long ToUnixTimeMs(this DateTime dateTime)
         {
             var universal = ToDateTimeSinceUnixEpoch(dateTime);
@@ -64,7 +63,7 @@ private static TimeSpan ToDateTimeSinceUnixEpoch(this DateTime dateTime)
             if (dateTime.Kind != DateTimeKind.Utc)
             {
                 dtUtc = dateTime.Kind == DateTimeKind.Unspecified && dateTime > DateTime.MinValue
-                    ? DateTime.SpecifyKind(dateTime.Subtract(LocalTimeZone.GetUtcOffset(dateTime)), DateTimeKind.Utc)
+                    ? DateTime.SpecifyKind(dateTime.Subtract(DateTimeSerializer.LocalTimeZone.GetUtcOffset(dateTime)), DateTimeKind.Utc)
                     : dateTime.ToStableUniversalTime();
             }