Service Client DateTime Time Zone Offset Compatability Issue

I'm attempting to communicate with a J开发者_JAVA技巧ava webservice via a .NET application, using a Visual Studio Service reference (System.ServiceModel namespace classes). I've found that whenever it serializes a DateTime value it does not specify the offset. The problem is two fold:

1. I can't figure out how to create a DateTime object with a specific time zone. I can create a DateTimeOffset that will accomplish this, but the service client is expecting a DateTime object.
2. When the DateTime object is serialized, it does not include the time zone offset.

To elaborate on issue #2, the XML that the service expects for the timestamp object is as follows:

  <startDate>2011-03-18T00:00:00-07:00</startDate>
  <endDate>2011-03-19T00:00:00-07:00</endDate>

However, the XML that I see when tracing the .NET app is as follows:

  <startDate>2011-03-18T00:00:00</startDate>
  <endDate>2011-03-19T00:00:00</endDate>

The web service requires the time zone, because the underlying data is tracked in GMT-0. The data that is returned is in daily intervals, so if I don't specify a time zone then I get data back for GMT-0. Only when I provide the offset in the query do I get the in the data correct time zone.

Suggestion: convert all your DateTimeOffset values to DateTime values in UTC and submit them to the webapp.

static DateTime ConvertFromDateTimeOffset(DateTimeOffset dateTime) {
   if (dateTime.Offset.Equals(TimeSpan.Zero))
      return dateTime.UtcDateTime;
   else if (dateTime.Offset.Equals(TimeZoneInfo.Local.GetUtcOffset(dateTime.DateTime)))
      return DateTime.SpecifyKind(dateTime.DateTime, DateTimeKind.Local);
   else
      return dateTime.DateTime;
}

From this page: A General-Purpose Conversion Method

Hope This Helps.