``
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <RTClib.h>
#include <BigFont01.h> // Include BigFont01 library

// Define I2C LCD pins
const int lcdAddr = 0x27;  // I2C address of LCD
const int lcdCols = 16;    // Number of columns
const int lcdRows = 2;     // Number of rows

// Define RTC pins
const int rtcCls = 5;      // SCL pin
const int rtcSda = 4;      // SDA pin

// Initialize LCD and RTC objects
LiquidCrystal_I2C lcd(lcdAddr, lcdCols, lcdRows);
RTC_DS1307 rtc;

void setup() {
  // Initialize serial communication
    Serial.begin(9600);

      // Initialize LCD
        lcd.init();
          lcd.backlight();

            // Initialize RTC
              rtc.begin();
                rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); // Set RTC time to compile time

                  // Print initial time on LCD with big font
                    printTimeBig();
                    }

                    void loop() {
                      // Update time every second
                        delay(1000);
                          printTimeBig();
                          }

                          void printTimeBig() {
                            DateTime now = rtc.now();

                              // Format time as HH:MM
                                char timeStr[6];
                                  sprintf(timeStr, "%02d:%02d", now.hour(), now.minute());

                                    // Clear LCD
                                      lcd.clear();

                                        // Set big font
                                          lcd.setFont(BigFont01);

                                            // Print time on LCD with big font
                                              lcd.setCursor(0, 0);
                                                lcd.print(timeStr);

                                                  // Reset font to default
                                                    lcd.setFont();
                                                    }