// For: https://forum.arduino.cc/t/lights-not-listening-to-buttons/1061418/

void setup() 
{
  pinMode(13, OUTPUT);             // declare pin 13 (BLUE LED) as output
  pinMode(7, OUTPUT);              // declare pin 7 (yellow LED) as output
  pinMode(12, INPUT);              // NIGHT BUTTON
  pinMode(6, INPUT);               // DAY BUTTON
}

void loop() 
{
  if (digitalRead(12) == HIGH)     // if the NIGHT button is pressed:
  {
    digitalWrite(13, HIGH);        // turn the blue LED on pin 13 ON
    digitalWrite(7, LOW);          // turn the yellow LED on pin 7 OFF
  }
  else if (digitalRead(6) == HIGH) // if the DAY button is  pressed:
  {
    digitalWrite(13, LOW);         // turn the blue LED on pin 3 OFF
    digitalWrite(7, HIGH);         // turn the yellow LED on pin 7 ON
  }
}