timezone and date of my appointment dose not work correctly????

hello my friends
I have write a application that send appointment to outlook with asp.net and c#.i need to send date in shamsi date format,and my time zone set to tehran GMT(+03:30).but timezone and date dose not work correctly.for example when i send an appointment with start time=06.30 and end time=12.00 ,the client receive start time=12.30 and end time=1.30, and date dose not receive in shamsi date format!!!
my code is:
            sbICSFile.AppendLine("BEGIN:VCALENDAR");
            sbICSFile.AppendLine("VERSION:2.0");
            sbICSFile.AppendLine("PRODID:-//Tehran/");
            sbICSFile.AppendLine("BEGIN:VEVENT");
         & ...