zone

/*
 *  call-seq:
 *     time.zone => string
 *  
 *  Returns the name of the time zone used for <i>time</i>. As of Ruby
 *  1.8, returns ``UTC'' rather than ``GMT'' for UTC times.
 *     
 *     t = Time.gm(2000, "jan", 1, 20, 15, 1)
 *     t.zone   #=> "UTC"
 *     t = Time.local(2000, "jan", 1, 20, 15, 1)
 *     t.zone   #=> "CST"
 */

static VALUE
time_zone(time)
    VALUE time;
{
    struct time_object *tobj;
#if !defined(HAVE_TM_ZONE) && (!defined(HAVE_TZNAME) || !defined(HAVE_DAYLIGHT))
    char buf[64];
    int len;
#endif
    
    GetTimeval(time, tobj);
    if (tobj->tm_got == 0) {
        time_get_tm(time, tobj->gmt);
    }

    if (tobj->gmt == 1) {
        return rb_str_new2("UTC");
    }
#if defined(HAVE_TM_ZONE)
    return rb_str_new2(tobj->tm.tm_zone);
#elif defined(HAVE_TZNAME) && defined(HAVE_DAYLIGHT)
    return rb_str_new2(tzname[daylight && tobj->tm.tm_isdst]);
#else
    len = strftime(buf, 64, "%Z", &tobj->tm);
    return rb_str_new(buf, len);
#endif
}