#include "RTClib.h"
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);
RTC_DS1307 rtc;

const char* days[] = {"Sun.", "Mon.", "Tue.", "Wed.", "Thu.", "Fri.", "Sat."};

void setup() {
  Serial.begin(115200);

  lcd.init();
  lcd.backlight();

  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    Serial.flush();
    abort();
  }
}

void loop() {
  char timeBuffer[9]; // HH:MM:SS
  char dateBuffer[16];
  DateTime now = rtc.now();
  const char* dayName = days[now.dayOfTheWeek()];

  sprintf(timeBuffer, "%02d:%02d:%02d", now.hour(), now.minute(), now.second());

  lcd.setCursor(4, 0);
  lcd.print(timeBuffer);
  
  sprintf(dateBuffer, "%s %02d/%02d/%04d", dayName, now.day(), now.month(), now.year());
  
  lcd.setCursor(1, 1);
  lcd.print(dateBuffer); 

  delay(1000);
}