time.c:1090
static VALUE
time_wday(time)
    VALUE time;
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    if (tobj->tm_got == 0) {
	time_get_tm(time, tobj->gmt);
    }
    return INT2FIX(tobj->tm.tm_wday);
}
