Particle Electron: 1 year of temperature monitor data

Troubleshooting
3 
#define publish_cycle 30000 
unsigned int lastPublish = 0;

int led = D7;
double reading = 0.0;
double mvolts = 0.0;
double tempC = 0.0;
double tempF = 0.0;
boolean flag = false;

double readingl=0.0;

void setup() {
    pinMode(led,OUTPUT);
    Particle.keepAlive(120);
    Particle.function("led", ledStatus);

}

void loop() {
    unsigned long now = millis();
    reading = analogRead(A0);
    mvolts = (reading * 3300.0)/4095.0;
    mvolts = mvolts -500.0;
    tempC = mvolts/10.0;
    tempF = (tempC*1.8) + 32.0;
    readingl = analogRead(A1);
    
   //to IFTTT
    if ( tempC > 26.0 && flag == false){
    Particle.publish("toohot");
    flag = true;
    }
    if (tempC < 24.0 && flag == true){
    Particle.publish("tempnormal");
    flag = false;
    }

    
    if ((now - lastPublish) > publish_cycle) {
    //to LOSANT
    Particle.publish("temp-reading", String(tempC), PRIVATE) ;
    Particle.publish("light-intensity",String(readingl), PRIVATE) ;
    delay(500);
    //to ThingSpeak
    Particle.publish("temperature", "{ \"1\": \"" + String(tempC) + "\"," + "\"2\": \"" + String(readingl) + "\"}", PRIVATE);
    lastPublish = now;
    }
    

}

int ledStatus(String command){
    if(command.equalsIgnoreCase("on")){
        digitalWrite(led,HIGH);
        return 1;
    }
    else if (command.equalsIgnoreCase("off")){
        digitalWrite(led,LOW);
        return 0;
    }
    else{
        return -1;
    }
    
}