Arduino Uno con ethernet shield W5100 - UV Meter

Hola amigos, les paso mi proyecto que una mezcla de los encontró por la web y con ayuda de otro amigo lo desarrollamos de tal manera que pueda publicar online via Twitter, aquí el código:

#include <TimeLib.h>
#include <SPI.h> // needed in Arduino 0019 or later
#include <Ethernet.h>
#include <Twitter.h>
#include <EthernetUdp.h>
#include <Time.h>

String UV = "0"; 

const long oneSecond = 1000;  // a second is a thousand milliseconds
const long oneMinute = oneSecond * 60;
const long halfHour = oneMinute * 30;
const long oneHour   = oneMinute * 60;
const long oneDay    = oneHour * 24;
const long tenMinute = oneMinute * 10;

// The includion of EthernetDNS is not needed in Arduino IDE 1.0 or later.
// Please uncomment below in Arduino IDE 0022 or earlier.
//#include <EthernetDNS.h>

// Ethernet Shield Settings
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
// NTP Servers:
IPAddress timeServer(132, 163, 4, 101); // time-a.timefreq.bldrdoc.gov
// IPAddress timeServer(132, 163, 4, 102); // time-b.timefreq.bldrdoc.gov
// IPAddress timeServer(132, 163, 4, 103); // time-c.timefreq.bldrdoc.gov

//const int timeZone = 1;     // Central European Time
const int timeZone = -5;  // Eastern Standard Time (USA)
//const int timeZone = -4;  // Eastern Daylight Time (USA)
//const int timeZone = -8;  // Pacific Standard Time (USA)
//const int timeZone = -7;  // Pacific Daylight Time (USA)

EthernetUDP Udp;
unsigned int localPort = 8888;  // local port to listen for UDP packets

// If you don't specify the IP address, DHCP is used(only in Arduino 1.0 or later).
byte ip[] = { 192, 168, 1, 22 };
//byte ip[] = {  };

// Your Token to Tweet (get it from http://arduino-tweet.appspot.com/)
Twitter twitter("twittertoken");

// First message to post
char msg[140]; // mensaje de inicio personalizado
char buff[140];

time_t date = 0; // when the digital clock was displayed

void setup() {
  // put your setup code here, to run once:
  if (!Ethernet.begin(mac))  // Try to connect using DHCP
    Ethernet.begin(mac, ip); // Try to connect using a Static IP address.
  delay(100);
  Serial.begin(9600);
  Serial.print(F("Connected to IP address: "));  // Print out the IP address.
  for (int i = 0; i < 4; i++)
    {
      Serial.print(Ethernet.localIP()[i], DEC);
      Serial.print("."); 
    }
  Serial.println();
  Serial.println();
  
  Serial.println("connecting ...");
  
  Udp.begin(localPort);
  Serial.println("waiting for sync");
  setSyncProvider(getNtpTime);

  if (timeStatus() != timeNotSet) {
    if (now() != date) { //update the display only if time has changed
      date = now();
    }
  }

  // Personaliza tu mensaje de inicio...
  sprintf(msg, "%d/%d/%d - %d horas con %d minutos, @WSILIMALIM7 periodo de pruebas UV Meter.....", day(date), month(date), year(date), hour(date), minute(date));
  
  if (twitter.post(msg)) {
    // Specify &Serial to output received response to Serial.
    // If no output is required, you can just omit the argument, e.g.
    // int status = twitter.wait();
    int status = twitter.wait(&Serial);
    if (status == 200) {
      Serial.println("OK.");
    } else {
      Serial.print("failed : code ");
      Serial.println(status);
    }
  } else {
    Serial.println("connection failed.");
  }
  
}

void loop() {
  // put your main code here, to run repeatedly:
  if (timeStatus() != timeNotSet) {
    if (now() != date) { //update the display only if time has changed
      date = now();
    }
  }
  UV = readSensor();
  //Serial.println(UV); //enviar índice UV al monitor serial
  int uv_int = UV.toInt();
  sprintf(buff, "%d/%d/%d - %dhrs y %dmin, Indice UV en el Distrito de Miraflores: %d #ArduinoEthernet", day(date), month(date), year(date), hour(date), minute(date), uv_int);
  tweet(buff);
  delay(tenMinute); //oneDay...

}

String readSensor()
{
  String UVIndex = "0";
  int sensorValue = 0;
  
  sensorValue = analogRead(A4);                        //connect UV sensor to Analog 0   
  int voltage = (sensorValue * (5.0 / 1023.0))*1000;  //Voltage in miliVolts
  
  if(voltage<50)
  {
    UVIndex = "0";
  }else if (voltage>50 && voltage<=227)
  {
    UVIndex = "0";
  }else if (voltage>227 && voltage<=318)
  {
    UVIndex = "1";
  }
  else if (voltage>318 && voltage<=408)
  {
    UVIndex = "2";
  }else if (voltage>408 && voltage<=503)
  {
    UVIndex = "3";
  }
  else if (voltage>503 && voltage<=606)
  {
    UVIndex = "4";
  }else if (voltage>606 && voltage<=696)
  {
    UVIndex = "5";
  }else if (voltage>696 && voltage<=795)
  {
    UVIndex = "6";
  }else if (voltage>795 && voltage<=881)
  {
    UVIndex = "7";
  }
  else if (voltage>881 && voltage<=976)
  {
    UVIndex = "8";
  }
  else if (voltage>976 && voltage<=1079)
  {
    UVIndex = "9";
  }
  else if (voltage>1079 && voltage<=1170)
  {
    UVIndex = "10";
  }else if (voltage>1170)
  {
    UVIndex = "11";
  }
  return UVIndex;
  
}

void tweet(char msg[]) {
  Serial.println("connecting ...");
  if (twitter.post(msg)) {
    int status = twitter.wait(&Serial);
    if (status == 200) {
      Serial.println("OK.");
    } else {
      Serial.print("failed : code ");
      Serial.println(status);
    }
  } else {
    Serial.println("connection failed.");
  }

}

/*-------- NTP code ----------*/

const int NTP_PACKET_SIZE = 48; // NTP time is in the first 48 bytes of message
byte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming & outgoing packets

time_t getNtpTime()
{
  while (Udp.parsePacket() > 0) ; // discard any previously received packets
  Serial.println("Transmit NTP Request");
  sendNTPpacket(timeServer);
  uint32_t beginWait = millis();
  while (millis() - beginWait < 1500) {
    int size = Udp.parsePacket();
    if (size >= NTP_PACKET_SIZE) {
      Serial.println("Receive NTP Response");
      Udp.read(packetBuffer, NTP_PACKET_SIZE);  // read packet into the buffer
      unsigned long secsSince1900;
      // convert four bytes starting at location 40 to a long integer
      secsSince1900 =  (unsigned long)packetBuffer[40] << 24;
      secsSince1900 |= (unsigned long)packetBuffer[41] << 16;
      secsSince1900 |= (unsigned long)packetBuffer[42] << 8;
      secsSince1900 |= (unsigned long)packetBuffer[43];
      return secsSince1900 - 2208988800UL + timeZone * SECS_PER_HOUR;
    }
  }
  Serial.println("No NTP Response :-(");
  return 0; // return 0 if unable to get the time
}

// send an NTP request to the time server at the given address
void sendNTPpacket(IPAddress &address)
{
  // set all bytes in the buffer to 0
  memset(packetBuffer, 0, NTP_PACKET_SIZE);
  // Initialize values needed to form NTP request
  // (see URL above for details on the packets)
  packetBuffer[0] = 0b11100011;   // LI, Version, Mode
  packetBuffer[1] = 0;     // Stratum, or type of clock
  packetBuffer[2] = 6;     // Polling Interval
  packetBuffer[3] = 0xEC;  // Peer Clock Precision
  // 8 bytes of zero for Root Delay & Root Dispersion
  packetBuffer[12]  = 49;
  packetBuffer[13]  = 0x4E;
  packetBuffer[14]  = 49;
  packetBuffer[15]  = 52;
  // all NTP fields have been given values, now
  // you can send a packet requesting a timestamp:                 
  Udp.beginPacket(address, 123); //NTP requests are to port 123
  Udp.write(packetBuffer, NTP_PACKET_SIZE);
  Udp.endPacket();
}

Hasta hace un tiempo atrás todo funcionaba de maravilla, pero ahora tengo el siguiente error Dropbox - Captura de pantalla 2018-04-02 12.16.05.png - Simplify your life, me sale como fecha 0/0/1970 y horas y minutos en cero (0).

Cuando entro al Monitor Serie, tengo el siguiente error y no se como resolverlo:

Connected to IP address: 192.168.1.22.

connecting ...
waiting for sync
Transmit NTP Request
No NTP Response :-(
HTTP/1.0 403 Forbidden
Content-Type: text/html; charset=utf-8
Cache-Control: no-cache
X-Cloud-Trace-Context: 8dfc24537334dff17591413e21a889c3
Date: Mon, 02 Apr 2018 17:03:44 GMT
Server: Google Frontend
Content-Length: 73

Error 403 - {"errors":[{"code":187,"message":"Status is a duplicate."}]}
failed : code 403
connecting ...
HTTP/1.0 403 Forbidden
Content-Type: text/html; charset=utf-8
Cache-Control: no-cache
X-Cloud-Trace-Context: a21e8625771fa581e247f283b625ae15;o=1
Date: Mon, 02 Apr 2018 17:03:45 GMT
Server: Google Frontend
Content-Length: 73

Error 403 - {"errors":[{"code":187,"message":"Status is a duplicate."}]}
failed : code 403

Por favor si alguien me pudiera ayudar, se los voy a agradecer bastante, mil gracias

PD: el proyecto original del UV meter es: https://www.instructables.com/id/DIY-UV-Meter-With-Arduino-and-a-Nokia-5110-Display/