UTC/GMT time using UDP

Extracting data from ntp servers is very easy using an ESP8266 and/or Arduino ethernet or wifi. Since I absolutely love Processing for it's awesome libraries, flexibility, and easy to use IDE I decided to give it a spin using the following as a reference: https://www.arduino.cc/en/Tutorial/UdpNtpClient. Since Processing's support for the 'long' data type is mostly useless parsing up the received packet got pretty messy. The program is doing exactly what I want but before going any further I'd like to know if there is any better way to parse up the received packet. Thank you for looking.

// import UDP library
import hypermedia.net.*;

UDP udp;  // define the UDP object

byte packetBuff[] = new byte[48];

void setup()
{
  size(175, 100);
  // create a new datagram connection on port 8888
  // and wait for an incoming message
  udp = new UDP( this, 8888 );
  udp.listen( true );

  for (int i = 0; i < 48; i += 1) packetBuff[i] = 0; // fill packetBuff with 0's

  packetBuff[0]   = byte(227);   // LI, Version, Mode
  packetBuff[1]   = 0;           // Stratum, or type of clock
  packetBuff[2]   = 6;           // Polling Interval
  packetBuff[3]   = byte(236);   // Peer Clock Precision
  // 8 bytes of zero for Root Delay & Root Dispersion
  packetBuff[12]  = 49;
  packetBuff[13]  = 78;
  packetBuff[14]  = 49;
  packetBuff[15]  = 52;
  // all NTP fields have been given values, now
  // you can send a packet requesting a timestamp:
}

//process events
void draw() {
}


void mouseClicked()
{
  String ip   = "time.nist.gov";      // the destination IP
  //String ip     = "us.pool.ntp.org";    // the destination IP
  int port      = 123;                  // the destination port
  // send the buffer
  udp.send(packetBuff, ip, port );
  background(random(256), random(256), random(256));
}


void receive( byte[] data )  // <-- default handler
{

  for (int i = 0; i < 48; i += 1)
  {
    int k = data[i] & 0xFF;
    if (i >= 40 && i < 44) println("data[" + i + "]" + " = " + k);
  }

  int ab = data[40] & 0xFF; // data[40 to 43] hi byte to low byte
  int ac = data[41] & 0xFF; // is seconds since January 1 1900 (UNIX time)
  int ad = data[42] & 0xFF;
  int ae = data[43] & 0xFF;

  int af = ((ab << 24)+(ac << 16)+(ad << 8)+(ae));
  af -= 1104494400; // subtract 2208988800 seconds for 70 years in two chunks
  af -= 1104494400; // af = signed number that represents seconds since January 1 1970

  // convert to UTC/GMT time
  int ag = Integer.remainderUnsigned(af, 86400); // get modulus using seconds in 24 hours
  ag /= 3600; // extract hours
  String ah = Integer.toUnsignedString(af); // thank you Java 8 Integer class :)
  println("Seconds since January 1 1970 = " + ah);

  print("UTC/GMT time = " + ag + ":"); // hours

  // In the first 10 minutes of each hour print a leading '0'
  if (((af % 3600) / 60) < 10)  print('0');

  //print the minute (3600 equals secs per minute)
  println((af  % 3600) / 60);
  println();
}