DateTimeZone {
/* Константы */
const integer AFRICA = 1 ;
const integer AMERICA = 2 ;
const integer ANTARCTICA = 4 ;
const integer ARCTIC = 8 ;
const integer ASIA = 16 ;
const integer ATLANTIC = 32 ;
const integer AUSTRALIA = 64 ;
const integer EUROPE = 128 ;
const integer INDIAN = 256 ;
const integer PACIFIC = 512 ;
const integer UTC = 1024 ;
const integer ALL = 2047 ;
const integer ALL_WITH_BC = 4095 ;
const integer PER_COUNTRY = 4096 ;

const EUROPE = 128

decbin (128);

$arr = DateTimeZone::listIdentifiers(DateTimeZone::AMERICA);
 echo $arr [35]; /*получаем America/Chicago*/

const integer AMERICA = 2 ;