timezone_identifiers_list Returns numerically index array with all timezone identifiers &reftitle.description; arraytimezone_identifiers_list intwhat stringoption arrayDateTimeZone::listIdentifiers intwhat stringcountry &reftitle.parameters; &date.datetime.description; what One of DateTimeZone class constants, defaults to DateTimeZone::ALL. country A two-letter ISO 3166-1 compatible country code. &reftitle.returnvalues; Returns array on success or &false; on failure. &reftitle.examples; A <function>timezone_identifiers_list</function> example ]]> &example.outputs.similar; &reftitle.seealso; timezone_abbreviations_list