INMCM

I've made a modification to to Chris's code so that you can compensate for timezones. It's just an extra argument that is the time difference between UTC and the timezone you want to set the Netduino to.

public static DateTime NTPTime(String TimeServer, int UTC_offset)
        {
            // Find endpoint for timeserver
            IPEndPoint ep = new IPEndPoint(Dns.GetHostEntry(TimeServer).AddressList[0], 123);

            // Connect to timeserver
            Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            s.Connect(ep);

            // Make send/receive buffer
            byte[] ntpData = new byte[48];
            Array.Clear(ntpData, 0, 48);

            // Set protocol version
            ntpData[0] = 0x1B;

            // Send Request
            s.Send(ntpData);

            // Receive Time
            s.Receive(ntpData);

            byte offsetTransmitTime = 40;

            ulong intpart = 0;
            ulong fractpart = 0;

            for (int i = 0; i <= 3; i++)
                intpart = (intpart << 8) | ntpData[offsetTransmitTime + i];

            for (int i = 4; i <= 7; i++)
                fractpart = (fractpart << 8) | ntpData[offsetTransmitTime + i];

            ulong milliseconds = (intpart * 1000 + (fractpart * 1000) / 0x100000000L);

            s.Close();

            TimeSpan timeSpan = TimeSpan.FromTicks((long)milliseconds * TimeSpan.TicksPerMillisecond);
            DateTime dateTime = new DateTime(1900, 1, 1);
            dateTime += timeSpan;
            
            TimeSpan offsetAmount = new TimeSpan(0, UTC_offset, 0, 0, 0);
            DateTime networkDateTime = (dateTime + offsetAmount);

            return networkDateTime;
        }

So if you were in the Eastern time zone of the United States, you just call:

Utility.SetLocalTime(NTPTime("time-a.nist.gov", -5));