GetTimeFromTimeServer.linq

<Query Kind="Program">
  <Namespace>System.Net</Namespace>
  <Namespace>System.Net.Sockets</Namespace>
</Query>

//https://stackoverflow.com/questions/1193955/how-to-query-an-ntp-server-using-c
void Main()
{
	GetNetworkTime().Dump();
	GetNetworkTime("time.windows.com").Dump();
}

public static DateTime GetNetworkTime(string ntpServer = "pool.ntp.org")
{
	var ntpData = new byte[48];
	ntpData[0] = 0x1B; //LeapIndicator = 0 (no warning), VersionNum = 3 (IPv4 only), Mode = 3 (Client Mode)

	var addresses = Dns.GetHostEntry(ntpServer).AddressList;
	var ipEndPoint = new IPEndPoint(addresses[0], 123);
	var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

	socket.Connect(ipEndPoint);
	socket.Send(ntpData);
	socket.Receive(ntpData);
	socket.Close();

	ulong intPart = (ulong)ntpData[40] << 24 | (ulong)ntpData[41] << 16 | (ulong)ntpData[42] << 8 | (ulong)ntpData[43];
	ulong fractPart = (ulong)ntpData[44] << 24 | (ulong)ntpData[45] << 16 | (ulong)ntpData[46] << 8 | (ulong)ntpData[47];

	var milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);
	var networkDateTime = (new DateTime(1900, 1, 1)).AddMilliseconds((long)milliseconds);

	return networkDateTime;
}