Calender C Program

main.c

#include <stdio.h>

int get_starter(int year) {
    int day = (((year - 1) * 365) + ((year - 1) / 4) - ((year - 1) / 100) + ((year) / 400) + 1) % 7;
    return day;
}

int main() {
    int year, month, date, dayinM, dayinW = 0, starter;
    printf("\n ENTER THE YEAR:");
    scanf("%d", &year);

    char *months[] = {"JANUARY", "FEBRUARY", "MARCH", "APRIL", "MAY", "JUNE", "JULY", "AUGUST", "SEPTEMBER", "OCTOBER",
                      "NOVEMBER", "DECEMBER"};
    int monthDay[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

    if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
        monthDay[1] = 29;
    starter = get_starter(year);

    for (month = 0; month < 12; month++) {
        dayinM = monthDay[month];;
        printf("\n\n____________________%s____________________\n", months[month]);
        printf("\n   SUN   MON   TUE   WED   THU   FRI   SAT\n");
        for (dayinW = 0; dayinW < starter; dayinW++)
            printf("      ");

        for (date = 1; date <= dayinM; date++) {
            printf("%6d", date);
            if (++dayinW > 6) {
                printf("\n");
                dayinW = 0;
            }
        }
        starter = dayinW;
    }
}