The whole code

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <string.h>
//Code by Ninto

int main()
{
    int duration = 10; //Introducing variables
    int hr, min, sec, r, togo = 0;
    int hours, minutes, seconds, day, month, year;
    int cycles = 0;
    int plus = 0;
    int minus = 0;
    int plusminus = 0;
    char fileSpec[255];

    //TIME for file name
    time_t now;
    time(&now);
    printf("Today is : %s", ctime(&now));
    struct tm *local = localtime(&now);

    hours = local->tm_hour;
    minutes = local->tm_min;
    seconds = local->tm_sec;

    day = local->tm_mday;
    month = local->tm_mon + 1;
    year = local->tm_year + 1900;

    //Time block end

    //create file
    FILE *fPointer;
    snprintf(fileSpec, "%04d_%02d_%02d_%02d:%02d.txt", year, month, day, hours, minutes); //From another post. I do not exactly know the syntax
    fPointer = fopen(fileSpec, "w");
    fprintf(fPointer, "Date and Time of creation: %d/%d/%d %d:%d:%d\n", day, month, year, hours, minutes, seconds);
    for (int i = 0; i < duration; i++) //Main calculating block
    {
        srand(time(NULL));
        r = 10000 - rand() % 20000; //random number + adding to plus/minus
        if (r > 0)
        {
            plus++;
            plusminus--;
        }
        else if (r < 0)
        {
            minus++;
            plusminus--;
        }

        printf("Current number:%d\n", r); //output and ETA calculation
        fprintf(fPointer, "%d\n", r);
        togo = duration - cycles;
        hr = (int)(togo / 3600);
        min = ((int)(togo / 60)) % 60;
        sec = (int)(togo % 60);
        printf("ETA: %02d:%02d:%02d\n", hr, min, sec);
        hr = 0;
        min = 0;
        sec = 0;
        r = 0;
        cycles++;
        sleep(1);
    }

    printf("\n\n\n\nDONE\nDONE\n\n"); //Final result
    printf("difference: %d\n", plusminus);
    printf("positive:  %d\n", plus);
    printf("negative: %d\n", minus);
    printf("cycles: %d", cycles);

    //Final result in file
    fprintf(fPointer, "difference: %d\n", plusminus);
    fprintf(fPointer, "positive:  %d\n", plus);
    fprintf(fPointer, "negative: %d\n", minus);
    fprintf(fPointer, "cycles: %d", cycles);
    printf("\nFile written\n");
    fclose(fPointer);
    while (1) //endless loop
    {
        r = r;
    }
    return 0;
}