ThingSpeak

Hello. I am working on a project to monitor agricultural variables. The module that I designed transmits the data by GSM, with the SIM800 module every 30 minutes takes a sample. My problem is the following, I need to transmit the stored data every 2 hours every 30 minutes, but I don't know how to do that. In the line of code "GET / update? Api_key = EXNLVJJTBY17SM8V & field1 = ........", you can add the time of each sample. This would save energy by sending 4 data every 2 hours

if true
 altSerial.println("AT+CIPSHUT");delay(4000);
altSerial.println("AT+CIPSTATUS");

delay(5000);

   altSerial.println("AT+CIPMUX=0");

   delay(5000);

     altSerial.println("AT+CSTT=igprs.claro.com.ar");delay(2000);

     altSerial.println("AT+CIICR");delay(5000);

     altSerial.println("AT+CIFSR");delay(5000);

     //altSerial.println("AT+CIPSPRT=0");delay(4000);

     altSerial.println("AT+CIPSTART=\"TCP\",\"184.106.153.149\",\"80\"");delay(3000);

    //String mensaje

     String S_Bateria =String(Bateria,2);
     String Humedad_1 = String(S_Humedad_1,2);
     String Humedad_2 = String(S_Humedad_2,2);
     String fila = String("&field2=");
     String fila1 = String("&field3=");
     String stringUno= String("GET /update?api_key=EXNLVJJTBY17SM8U&field1=");
     String URL =String(stringUno + Humedad_1 + fila + Humedad_2 + fila1 + S_Bateria);
     int Largo=URL.length();
     Largo= Largo+3;
     String Memoria= String (String("AT+CIPSEND=")+String(Largo));

     altSerial.println(Memoria);delay(2000);

     altSerial.println(URL);altSerial.println("");

     //altSerial.println((char)26);puerto();delay(4000);
      delay(15000);
      altSerial.println("AT+CIPSHUT");delay(4000);
  end