int Sec = 0;  //Change the numbers from zero to set current time
int Min = 0;
int Hrs = 0;
bool PM = 0;

void setup() {
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay (1000);  //Runs the loop every 1 second
  Sec ++;
  if (Sec==59)  //On the 59th loop/sec increment minute and reset seconds
  {
    Min ++;
    Sec==0;
  }
  if (Min==59)   //On the 59th minute increment Hour and reset minutes
  {
    Hrs ++;
    Min==0;
  }
  if (Hrs==12)   //On the 12 Hour we set PM true and reset hour
  {
    PM=true;
    Hrs==0;
  }
  if (Hrs==12 && PM==1) //On the 2nd 12 Hour we set PM false and reset hour
  {
    PM=false;
    Hrs==0;
  }
  Serial.print(Hrs);
  Serial.print(":");
  Serial.print(Min);
  Serial.print(":");
  Serial.print(Sec);
  Serial.println(PM);
}