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Projects Programming
19

You're getting very close. I think you could do it like this:

      if ((now.hour() >= 10) && (now.hour() < 17)) 
      {
        lcd.setCursor(5, 3);
        lcd.print("Open window");
        delay(30);
      }
      else
      {
        lcd.setCursor(5, 3);
        lcd.print("Closed window");
        delay(30);
      }

since anything not inside the case is outside the case. But I think what you are looking for is this:

      if ((now.hour() >= 10) && (now.hour() < 17))
      {
        lcd.setCursor(5, 3);
        lcd.print("Open window");
        delay(30);
      }
      if ((now.hour() < 10) || (now.hour() >= 17)) 
      {
        lcd.setCursor(5, 3);
        lcd.print("Closed window");
        delay(30);
      }