#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 20, 4);

int DELAY_TIME = 300;
int lastTime = 0;
int timer = DELAY_TIME;
int cycle = 0;

void setup() {
  lcd.init();
  lcd.backlight();
}

void loop() {
  timer -= millis() - lastTime;

  if (timer <= 0) {
    timer = DELAY_TIME;
    lcd.clear();
    lcd.setCursor(16 - (cycle % 16), 0);
    lcd.print("Hello World!");
    cycle++;
  }

  lastTime = millis();
}