esp32 rtc
#include <LiquidCrystal_I2C.h>
#include "RTClib.h"

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

int day;
int month;
int year;
int hour;
int minute;
int second;

void setup() {
  rtc.begin();
  lcd.init();
  lcd.backlight();
} ////////////////////end loop

void loop() {
  DateTime now = rtc.now();
  day = now.day();
  month = now.month();
  year = now.year();
  hour = now.hour();
  minute = now.minute();
  second = now.second();

  //////////////////////////////date
  lcd.setCursor(0, 0);
  lcd.print("Date");
  lcd.setCursor(6, 0);

  if (day <= 9) {
    lcd.print("0");
  }
  lcd.print(day); 
  lcd.setCursor(8, 0);
  lcd.print("/");
  lcd.setCursor(9, 0);

  if (month <= 9) {
    lcd.print("0");
  }
  lcd.print(month);
  lcd.setCursor(11, 0);
  lcd.print("/");
  lcd.setCursor(12, 0);
  lcd.print(year);
  lcd.setCursor(0, 1);
  
   //////////////////////////////time
  lcd.print("Time");
  lcd.setCursor(6, 1);

  if (hour <= 9){       ////////////h
    lcd.print("0");
  }
  lcd.print(hour);
  lcd.setCursor(8, 1);
  lcd.print(":");
  lcd.setCursor(9, 1);

  if (minute <= 9) {    /////////////m
    lcd.print("0");
  }
  lcd.print(minute);
  lcd.setCursor(11, 1);
  lcd.print(":");
  lcd.setCursor(12, 1);

  if (second <= 9) {    //////////////s
    lcd.print("0");
  }
  lcd.print(second);
}   ////////////////////end loop