reqRequest.addbody adding hours to datettime

hi,


why when i do this 

var url = string.Format("application/updateapplicationfor/{0}/{1}", SourceSystemId, Guid.NewGuid()); var restRequest = new RestRequest(url, Method.POST) { RequestFormat = DataFormat.Json };
  <---- request.startdate = 2014/30/8:00am
restRequest.AddBody(request)'
<----------------added 6 hours ??? 
restrequest.parameters.startdate = 2014/30/2:oo pm 
var response = proxy.Execute<bool>(restRequest);


i have trieed to use the jsonserilizersettings 
var setting = new JsonSerializerSettings() { DateFormatHandling = DateFormatHandling.MicrosoftDateFormat }; JsonConvert.SerializeObject(restRequest, setting);

not working if anyone can give me advice i would love that