[APP] Gerador de Datas

/*==============================================================================
             _ ____        _____          __  __
            (_)  _ \ ___  |_   _|__  __ _|  \/  |
            | | |_) / __|   | |/ _ \/ _` | |\/| |
            | |  __/\__ \   | |  __/ (_| | |  | |
            |_|_|   |___/   |_|\___|\__,_|_|  |_|

               [iPs] Saber dia da Semana
                Criado por: [iPs]DraKiNs (agradecimentos a Crush)
                    Versão 0.1
==============================================================================*/

#include <stdio.h>

main()
{
    system("title [iPs TeaM] - Que dia da semana?");
    system("color 8f");

    int
        day = 0,
        month   = 0,
        year    = 0;

    // ==== [ Dia ] ========
    printf("Digite o dia: ");
    scanf("%d", &day);

    // ==== [ Mês ] ========
    printf("Digite o mês: ");
    scanf("%d", &month);

    // ==== [ Ano ] ========
    printf("Digite o ano: ");
    scanf("%d", &year);

    // ==== [ Processar ] ========

    char    sStr[24]    =   ("Dia Invalido");
    int
        iBissext    =   (year % 100),
        iWeekDay    =   (year / 100);

    if(month < 3) month += 12,year--;
    int iWeek = ((day + (month+1)*26/10 + iBissext + iBissext/4 + iWeekDay/4 - 2*iWeekDay) % 7);

    if(iWeek == 0) strcpy(sStr , ("Sábado"));
    if(iWeek == 1) strcpy(sStr , ("Domingo"));
    if(iWeek == 2) strcpy(sStr , ("Segunda"));
    if(iWeek == 3) strcpy(sStr , ("Terça"));
    if(iWeek == 4) strcpy(sStr ,  ("Quarta"));
    if(iWeek == 5) strcpy(sStr ,  ("Quinta")) ;
    if(iWeek == 6) strcpy(sStr ,  ("Sexta"));

    printf("O dia da semana desta data foi %s \n",sStr);
    return system("pause");
}