I’m new to programming in c. Currently trying to implement a licensing program on a machine and intend to use an atmega128 with a watch crystal to set the date such that it cannot be changed

#include <avr/io.h>
#include <avr/interrupt.h>

// Define RTC parameters
#define RTC_PRESCALER_VALUE 1024
#define RTC_OVERFLOW_COUNT 244   // Adjust this based on your RTC module's overflow count

volatile uint32_t system_time = 0;  // System time in milliseconds
volatile uint8_t seconds = 0;
volatile uint8_t minutes = 0;
volatile uint8_t hours = 0;
volatile uint8_t day = 1;
volatile uint8_t month = 1;
volatile uint16_t year = 2024; // Initial year

// Initialize RTC
void rtc_init() {
    // Configure RTC prescaler
    TCCR1B |= (1 << CS12) | (1 << CS10); // Set prescaler to 1024
    TIMSK |= (1 << TOIE1);  // Enable overflow interrupt
    TCNT1 = 0;  // Initialize timer counter
}

// RTC overflow interrupt handler
ISR(TIMER1_OVF_vect) {
    system_time += RTC_OVERFLOW_COUNT * (1000 / (F_CPU / RTC_PRESCALER_VALUE)); // Update system time

    // time
    seconds++;
    if (seconds >= 60) {
        seconds = 0;
        minutes++;
        if (minutes >= 60) {
            minutes = 0;
            hours++;
            if (hours >= 24) {
                hours = 0;
                day++;
                if (day > 30) { // Assuming all months have 30 days for simplicity
                    day = 1;
                    month++;
                    if (month > 12) {
                        month = 1;
                        year++;
                    }
                }
            }
        }
    }
}

int main() {}

I tried using the atmel avr atmega128 datasheet to understand how the counter works but to no avail