根据日期（年月日）求星期几

UINT8 MMI_GetWeekday(int rlYear, int rlMonth, int rlDay)
{
    int a, y, m, d, temp, temp1, temp2, temp3;

    a = (14 - rlMonth) / 12;
    y = rlYear - a;
    m = rlMonth + (12 * a) - 2;
    temp3 = rlDay + y + (y / 4);
    temp = y / 100;
    temp1 = y / 400;
    temp2 = (31 * m) / 12;
    d = temp3 - temp + temp1 + temp2;

    /* for alarm's week checking by chip, MMI needs to get a special week day,
        according to the week day of MMI_START_YEAR's 1/1. That day's week day should be 0 */
    //d = (d + 1) % 7;
    /* normal week day should be d = d % 7;*/
    d %= 7;

    return d;
}