string Date = "2009-02-25 16:13:00Z";
DateTime localDateTime = DateTime.Parse(Date);
DateTime utcDateTime = localDateTime.ToUniversalTime();
string nzTimeZoneKey = "New Zealand Standard Time";
TimeZoneInfo nzTimeZone = TimeZoneInfo.FindSystemTimeZoneById(nzTimeZoneKey);
DateTime nzDateTime = TimeZoneInfo.ConvertTimeFromUtc(utcDateTime, nzTimeZone);
Console.WriteLine("Date : {0}", Date);
Console.WriteLine(" localDateTime: {0}", localDateTime);
Console.WriteLine(" nzTimeZone: {0}", nzTimeZone);
Console.WriteLine(" : {0}", nzDateTime);
Console.ReadLine();