The only way to accomplish what you're doing, is by getting a pointer to the array rather than decaying the array to a pointer to the first element

int main() 
{
    int days[] = {1,2,3,4,5};
    int (*ptr)[5] = &days;
    printf("%u\n", sizeof(days));
    printf("%u\n", sizeof(*ptr));

    return 0;
}