=head1 NAME
Time::OlsonTZ::Data - Olson timezone data
=head1 SYNOPSIS
use Time::OlsonTZ::Data qw(olson_version);
$version = olson_version;
use Time::OlsonTZ::Data qw(
olson_canonical_names olson_link_names olson_all_names
olson_links olson_country_selection);
$names = olson_canonical_names;
$names = olson_link_names;
$names = olson_all_names;
$links = olson_links;
$countries = olson_country_selection;
use Time::OlsonTZ::Data qw(olson_tzfile);
$filename = olson_tzfile("America/New_York");
=head1 DESCRIPTION
This module encapsulates the Olson timezone database, providing binary
tzfiles and ancillary data. Each version of this module encapsulates
a particular version of the timezone database. It is intended to be
regularly updated, as the timezone database changes.
=cut
package Time::OlsonTZ::Data;
{ use 5.006; }
use warnings;
use strict;
our $VERSION = "0.201804";
use parent "Exporter";
our @EXPORT_OK = qw(
olson_version olson_code_version olson_data_version
olson_canonical_names olson_link_names olson_all_names
olson_links
olson_country_selection
olson_tzfile
);
my($datavol, $datadir);
sub _data_file($) {
my($upath) = @_;
unless(defined $datadir) {
require File::Spec;
($datavol, $datadir, undef) =
File::Spec->splitpath($INC{"Time/OlsonTZ/Data.pm"});
}
my @nameparts = split(/\//, $upath);
my $filename = pop(@nameparts);
return File::Spec->catpath($datavol,
File::Spec->catdir($datadir, "Data", @nameparts), $filename);
}
=head1 FUNCTIONS
=head2 Basic information
=over
=item olson_version
Returns the version number of the database that this module encapsulates.
Version numbers for the Olson database currently consist of a year number
and a lowercase letter, such as "C<2010k>"; they are not guaranteed to
retain this format in the future.
=cut
use constant olson_version => "2018d";
=item olson_code_version
Returns the version number of the code part of the database that this
module encapsulates. This is now always the same as the value returned
by L</olson_version>. Until late 2012 the database was distributed in
two parts, each with their own version number, so this was a distinct
piece of information.
=cut
use constant olson_code_version => "2018d";
=item olson_data_version
Returns the version number of the data part of the database that this
module encapsulates. This is now always the same as the value returned
by L</olson_version>. Until late 2012 the database was distributed in
two parts, each with their own version number, so this was a distinct
piece of information.
=cut
use constant olson_data_version => "2018d";
=back
=head2 Zone metadata
=over
=item olson_canonical_names
Returns the set of timezone names that this version of the database
defines as canonical. These are the timezone names that are directly
associated with a set of observance data. The return value is a reference
to a hash, in which the keys are the canonical timezone names and the
values are all C<undef>.
=cut
my $cn = q(+{ map { ($_ => undef) } qw(
Africa/Abidjan Africa/Accra Africa/Algiers Africa/Bissau Africa/Cairo
Africa/Casablanca Africa/Ceuta Africa/El_Aaiun Africa/Johannesburg
Africa/Juba Africa/Khartoum Africa/Lagos Africa/Maputo Africa/Monrovia
Africa/Nairobi Africa/Ndjamena Africa/Sao_Tome Africa/Tripoli
Africa/Tunis Africa/Windhoek America/Adak America/Anchorage
America/Araguaina America/Argentina/Buenos_Aires
America/Argentina/Catamarca America/Argentina/Cordoba
America/Argentina/Jujuy America/Argentina/La_Rioja
America/Argentina/Mendoza America/Argentina/Rio_Gallegos
America/Argentina/Salta America/Argentina/San_Juan
America/Argentina/San_Luis America/Argentina/Tucuman
America/Argentina/Ushuaia America/Asuncion America/Atikokan
America/Bahia America/Bahia_Banderas America/Barbados America/Belem
America/Belize America/Blanc-Sablon America/Boa_Vista America/Bogota
America/Boise America/Cambridge_Bay America/Campo_Grande America/Cancun
America/Caracas America/Cayenne America/Chicago America/Chihuahua
America/Costa_Rica America/Creston America/Cuiaba America/Curacao
America/Danmarkshavn America/Dawson America/Dawson_Creek America/Denver
America/Detroit America/Edmonton America/Eirunepe America/El_Salvador
America/Fort_Nelson America/Fortaleza America/Glace_Bay America/Godthab
America/Goose_Bay America/Grand_Turk America/Guatemala America/Guayaquil
America/Guyana America/Halifax America/Havana America/Hermosillo
America/Indiana/Indianapolis America/Indiana/Knox
America/Indiana/Marengo America/Indiana/Petersburg
America/Indiana/Tell_City America/Indiana/Vevay
America/Indiana/Vincennes America/Indiana/Winamac America/Inuvik
America/Iqaluit America/Jamaica America/Juneau
America/Kentucky/Louisville America/Kentucky/Monticello America/La_Paz
America/Lima America/Los_Angeles America/Maceio America/Managua
America/Manaus America/Martinique America/Matamoros America/Mazatlan
America/Menominee America/Merida America/Metlakatla America/Mexico_City
America/Miquelon America/Moncton America/Monterrey America/Montevideo
America/Nassau America/New_York America/Nipigon America/Nome
America/Noronha America/North_Dakota/Beulah America/North_Dakota/Center
America/North_Dakota/New_Salem America/Ojinaga America/Panama
America/Pangnirtung America/Paramaribo America/Phoenix
America/Port-au-Prince America/Port_of_Spain America/Porto_Velho
America/Puerto_Rico America/Punta_Arenas America/Rainy_River
America/Rankin_Inlet America/Recife America/Regina America/Resolute
America/Rio_Branco America/Santarem America/Santiago
America/Santo_Domingo America/Sao_Paulo America/Scoresbysund
America/Sitka America/St_Johns America/Swift_Current America/Tegucigalpa
America/Thule America/Thunder_Bay America/Tijuana America/Toronto
America/Vancouver America/Whitehorse America/Winnipeg America/Yakutat
America/Yellowknife Antarctica/Casey Antarctica/Davis
Antarctica/DumontDUrville Antarctica/Macquarie Antarctica/Mawson
Antarctica/Palmer Antarctica/Rothera Antarctica/Syowa Antarctica/Troll
Antarctica/Vostok Asia/Almaty Asia/Amman Asia/Anadyr Asia/Aqtau
Asia/Aqtobe Asia/Ashgabat Asia/Atyrau Asia/Baghdad Asia/Baku
Asia/Bangkok Asia/Barnaul Asia/Beirut Asia/Bishkek Asia/Brunei
Asia/Chita Asia/Choibalsan Asia/Colombo Asia/Damascus Asia/Dhaka
Asia/Dili Asia/Dubai Asia/Dushanbe Asia/Famagusta Asia/Gaza Asia/Hebron
Asia/Ho_Chi_Minh Asia/Hong_Kong Asia/Hovd Asia/Irkutsk Asia/Jakarta
Asia/Jayapura Asia/Jerusalem Asia/Kabul Asia/Kamchatka Asia/Karachi
Asia/Kathmandu Asia/Khandyga Asia/Kolkata Asia/Krasnoyarsk
Asia/Kuala_Lumpur Asia/Kuching Asia/Macau Asia/Magadan Asia/Makassar
Asia/Manila Asia/Nicosia Asia/Novokuznetsk Asia/Novosibirsk Asia/Omsk
Asia/Oral Asia/Pontianak Asia/Pyongyang Asia/Qatar Asia/Qyzylorda
Asia/Riyadh Asia/Sakhalin Asia/Samarkand Asia/Seoul Asia/Shanghai
Asia/Singapore Asia/Srednekolymsk Asia/Taipei Asia/Tashkent Asia/Tbilisi
Asia/Tehran Asia/Thimphu Asia/Tokyo Asia/Tomsk Asia/Ulaanbaatar
Asia/Urumqi Asia/Ust-Nera Asia/Vladivostok Asia/Yakutsk Asia/Yangon
Asia/Yekaterinburg Asia/Yerevan Atlantic/Azores Atlantic/Bermuda
Atlantic/Canary Atlantic/Cape_Verde Atlantic/Faroe Atlantic/Madeira
Atlantic/Reykjavik Atlantic/South_Georgia Atlantic/Stanley
Australia/Adelaide Australia/Brisbane Australia/Broken_Hill
Australia/Currie Australia/Darwin Australia/Eucla Australia/Hobart
Australia/Lindeman Australia/Lord_Howe Australia/Melbourne
Australia/Perth Australia/Sydney CET CST6CDT EET EST EST5EDT Etc/GMT
Etc/GMT+1 Etc/GMT+10 Etc/GMT+11 Etc/GMT+12 Etc/GMT+2 Etc/GMT+3 Etc/GMT+4
Etc/GMT+5 Etc/GMT+6 Etc/GMT+7 Etc/GMT+8 Etc/GMT+9 Etc/GMT-1 Etc/GMT-10
Etc/GMT-11 Etc/GMT-12 Etc/GMT-13 Etc/GMT-14 Etc/GMT-2 Etc/GMT-3
Etc/GMT-4 Etc/GMT-5 Etc/GMT-6 Etc/GMT-7 Etc/GMT-8 Etc/GMT-9 Etc/UCT
Etc/UTC Europe/Amsterdam Europe/Andorra Europe/Astrakhan Europe/Athens
Europe/Belgrade Europe/Berlin Europe/Brussels Europe/Bucharest
Europe/Budapest Europe/Chisinau Europe/Copenhagen Europe/Dublin
Europe/Gibraltar Europe/Helsinki Europe/Istanbul Europe/Kaliningrad
Europe/Kiev Europe/Kirov Europe/Lisbon Europe/London Europe/Luxembourg
Europe/Madrid Europe/Malta Europe/Minsk Europe/Monaco Europe/Moscow
Europe/Oslo Europe/Paris Europe/Prague Europe/Riga Europe/Rome
Europe/Samara Europe/Saratov Europe/Simferopol Europe/Sofia
Europe/Stockholm Europe/Tallinn Europe/Tirane Europe/Ulyanovsk
Europe/Uzhgorod Europe/Vienna Europe/Vilnius Europe/Volgograd
Europe/Warsaw Europe/Zaporozhye Europe/Zurich Factory HST Indian/Chagos
Indian/Christmas Indian/Cocos Indian/Kerguelen Indian/Mahe
Indian/Maldives Indian/Mauritius Indian/Reunion MET MST MST7MDT PST8PDT
Pacific/Apia Pacific/Auckland Pacific/Bougainville Pacific/Chatham
Pacific/Chuuk Pacific/Easter Pacific/Efate Pacific/Enderbury
Pacific/Fakaofo Pacific/Fiji Pacific/Funafuti Pacific/Galapagos
Pacific/Gambier Pacific/Guadalcanal Pacific/Guam Pacific/Honolulu
Pacific/Kiritimati Pacific/Kosrae Pacific/Kwajalein Pacific/Majuro
Pacific/Marquesas Pacific/Nauru Pacific/Niue Pacific/Norfolk
Pacific/Noumea Pacific/Pago_Pago Pacific/Palau Pacific/Pitcairn
Pacific/Pohnpei Pacific/Port_Moresby Pacific/Rarotonga Pacific/Tahiti
Pacific/Tarawa Pacific/Tongatapu Pacific/Wake Pacific/Wallis WET
) });
sub olson_canonical_names() {
$cn = eval($cn) || die $@ if ref($cn) eq "";
return $cn;
}
=item olson_link_names
Returns the set of timezone names that this version of the database
defines as links. These are the timezone names that are aliases for
other names. The return value is a reference to a hash, in which the
keys are the link timezone names and the values are all C<undef>.
=cut
sub olson_links();
my $ln;
sub olson_link_names() {
return $ln ||= { map { ($_ => undef) } keys %{olson_links()} };
}
=item olson_all_names
Returns the set of timezone names that this version of the
database defines. These are the L</olson_canonical_names> and the
L</olson_link_names>. The return value is a reference to a hash, in
which the keys are the timezone names and the values are all C<undef>.
=cut
my $an;
sub olson_all_names() {
return $an ||= {
%{olson_canonical_names()},
%{olson_link_names()},
};
}
=item olson_links
Returns details of the timezone name links in this version of the
database. Each link defines one timezone name as an alias for some
other timezone name. The return value is a reference to a hash, in
which the keys are the aliases and each value is the canonical name of
the timezone to which that alias refers. All such canonical names can
be found in the L</olson_canonical_names> hash.
=cut
my $li = q(+{
"Africa/Addis_Ababa" => "Africa/Nairobi",
"Africa/Asmara" => "Africa/Nairobi",
"Africa/Asmera" => "Africa/Nairobi",
"Africa/Bamako" => "Africa/Abidjan",
"Africa/Bangui" => "Africa/Lagos",
"Africa/Banjul" => "Africa/Abidjan",
"Africa/Blantyre" => "Africa/Maputo",
"Africa/Brazzaville" => "Africa/Lagos",
"Africa/Bujumbura" => "Africa/Maputo",
"Africa/Conakry" => "Africa/Abidjan",
"Africa/Dakar" => "Africa/Abidjan",
"Africa/Dar_es_Salaam" => "Africa/Nairobi",
"Africa/Djibouti" => "Africa/Nairobi",
"Africa/Douala" => "Africa/Lagos",
"Africa/Freetown" => "Africa/Abidjan",
"Africa/Gaborone" => "Africa/Maputo",
"Africa/Harare" => "Africa/Maputo",
"Africa/Kampala" => "Africa/Nairobi",
"Africa/Kigali" => "Africa/Maputo",
"Africa/Kinshasa" => "Africa/Lagos",
"Africa/Libreville" => "Africa/Lagos",
"Africa/Lome" => "Africa/Abidjan",
"Africa/Luanda" => "Africa/Lagos",
"Africa/Lubumbashi" => "Africa/Maputo",
"Africa/Lusaka" => "Africa/Maputo",
"Africa/Malabo" => "Africa/Lagos",
"Africa/Maseru" => "Africa/Johannesburg",
"Africa/Mbabane" => "Africa/Johannesburg",
"Africa/Mogadishu" => "Africa/Nairobi",
"Africa/Niamey" => "Africa/Lagos",
"Africa/Nouakchott" => "Africa/Abidjan",
"Africa/Ouagadougou" => "Africa/Abidjan",
"Africa/Porto-Novo" => "Africa/Lagos",
"Africa/Timbuktu" => "Africa/Abidjan",
"America/Anguilla" => "America/Port_of_Spain",
"America/Antigua" => "America/Port_of_Spain",
"America/Argentina/ComodRivadavia" => "America/Argentina/Catamarca",
"America/Aruba" => "America/Curacao",
"America/Atka" => "America/Adak",
"America/Buenos_Aires" => "America/Argentina/Buenos_Aires",
"America/Catamarca" => "America/Argentina/Catamarca",
"America/Cayman" => "America/Panama",
"America/Coral_Harbour" => "America/Atikokan",
"America/Cordoba" => "America/Argentina/Cordoba",
"America/Dominica" => "America/Port_of_Spain",
"America/Ensenada" => "America/Tijuana",
"America/Fort_Wayne" => "America/Indiana/Indianapolis",
"America/Grenada" => "America/Port_of_Spain",
"America/Guadeloupe" => "America/Port_of_Spain",
"America/Indianapolis" => "America/Indiana/Indianapolis",
"America/Jujuy" => "America/Argentina/Jujuy",
"America/Knox_IN" => "America/Indiana/Knox",
"America/Kralendijk" => "America/Curacao",
"America/Louisville" => "America/Kentucky/Louisville",
"America/Lower_Princes" => "America/Curacao",
"America/Marigot" => "America/Port_of_Spain",
"America/Mendoza" => "America/Argentina/Mendoza",
"America/Montreal" => "America/Toronto",
"America/Montserrat" => "America/Port_of_Spain",
"America/Porto_Acre" => "America/Rio_Branco",
"America/Rosario" => "America/Argentina/Cordoba",
"America/Santa_Isabel" => "America/Tijuana",
"America/Shiprock" => "America/Denver",
"America/St_Barthelemy" => "America/Port_of_Spain",
"America/St_Kitts" => "America/Port_of_Spain",
"America/St_Lucia" => "America/Port_of_Spain",
"America/St_Thomas" => "America/Port_of_Spain",
"America/St_Vincent" => "America/Port_of_Spain",
"America/Tortola" => "America/Port_of_Spain",
"America/Virgin" => "America/Port_of_Spain",
"Antarctica/McMurdo" => "Pacific/Auckland",
"Antarctica/South_Pole" => "Pacific/Auckland",
"Arctic/Longyearbyen" => "Europe/Oslo",
"Asia/Aden" => "Asia/Riyadh",
"Asia/Ashkhabad" => "Asia/Ashgabat",
"Asia/Bahrain" => "Asia/Qatar",
"Asia/Calcutta" => "Asia/Kolkata",
"Asia/Chongqing" => "Asia/Shanghai",
"Asia/Chungking" => "Asia/Shanghai",
"Asia/Dacca" => "Asia/Dhaka",
"Asia/Harbin" => "Asia/Shanghai",
"Asia/Istanbul" => "Europe/Istanbul",
"Asia/Kashgar" => "Asia/Urumqi",
"Asia/Katmandu" => "Asia/Kathmandu",
"Asia/Kuwait" => "Asia/Riyadh",
"Asia/Macao" => "Asia/Macau",
"Asia/Muscat" => "Asia/Dubai",
"Asia/Phnom_Penh" => "Asia/Bangkok",
"Asia/Rangoon" => "Asia/Yangon",
"Asia/Saigon" => "Asia/Ho_Chi_Minh",
"Asia/Tel_Aviv" => "Asia/Jerusalem",
"Asia/Thimbu" => "Asia/Thimphu",
"Asia/Ujung_Pandang" => "Asia/Makassar",
"Asia/Ulan_Bator" => "Asia/Ulaanbaatar",
"Asia/Vientiane" => "Asia/Bangkok",
"Atlantic/Faeroe" => "Atlantic/Faroe",
"Atlantic/Jan_Mayen" => "Europe/Oslo",
"Atlantic/St_Helena" => "Africa/Abidjan",
"Australia/ACT" => "Australia/Sydney",
"Australia/Canberra" => "Australia/Sydney",
"Australia/LHI" => "Australia/Lord_Howe",
"Australia/NSW" => "Australia/Sydney",
"Australia/North" => "Australia/Darwin",
"Australia/Queensland" => "Australia/Brisbane",
"Australia/South" => "Australia/Adelaide",
"Australia/Tasmania" => "Australia/Hobart",
"Australia/Victoria" => "Australia/Melbourne",
"Australia/West" => "Australia/Perth",
"Australia/Yancowinna" => "Australia/Broken_Hill",
"Brazil/Acre" => "America/Rio_Branco",
"Brazil/DeNoronha" => "America/Noronha",
"Brazil/East" => "America/Sao_Paulo",
"Brazil/West" => "America/Manaus",
"Canada/Atlantic" => "America/Halifax",
"Canada/Central" => "America/Winnipeg",
"Canada/Eastern" => "America/Toronto",
"Canada/Mountain" => "America/Edmonton",
"Canada/Newfoundland" => "America/St_Johns",
"Canada/Pacific" => "America/Vancouver",
"Canada/Saskatchewan" => "America/Regina",
"Canada/Yukon" => "America/Whitehorse",
"Chile/Continental" => "America/Santiago",
"Chile/EasterIsland" => "Pacific/Easter",
Cuba => "America/Havana",
Egypt => "Africa/Cairo",
Eire => "Europe/Dublin",
"Etc/GMT+0" => "Etc/GMT",
"Etc/GMT-0" => "Etc/GMT",
"Etc/GMT0" => "Etc/GMT",
"Etc/Greenwich" => "Etc/GMT",
"Etc/Universal" => "Etc/UTC",
"Etc/Zulu" => "Etc/UTC",
"Europe/Belfast" => "Europe/London",
"Europe/Bratislava" => "Europe/Prague",
"Europe/Busingen" => "Europe/Zurich",
"Europe/Guernsey" => "Europe/London",
"Europe/Isle_of_Man" => "Europe/London",
"Europe/Jersey" => "Europe/London",
"Europe/Ljubljana" => "Europe/Belgrade",
"Europe/Mariehamn" => "Europe/Helsinki",
"Europe/Nicosia" => "Asia/Nicosia",
"Europe/Podgorica" => "Europe/Belgrade",
"Europe/San_Marino" => "Europe/Rome",
"Europe/Sarajevo" => "Europe/Belgrade",
"Europe/Skopje" => "Europe/Belgrade",
"Europe/Tiraspol" => "Europe/Chisinau",
"Europe/Vaduz" => "Europe/Zurich",
"Europe/Vatican" => "Europe/Rome",
"Europe/Zagreb" => "Europe/Belgrade",
GB => "Europe/London",
"GB-Eire" => "Europe/London",
GMT => "Etc/GMT",
"GMT+0" => "Etc/GMT",
"GMT-0" => "Etc/GMT",
GMT0 => "Etc/GMT",
Greenwich => "Etc/GMT",
Hongkong => "Asia/Hong_Kong",
Iceland => "Atlantic/Reykjavik",
"Indian/Antananarivo" => "Africa/Nairobi",
"Indian/Comoro" => "Africa/Nairobi",
"Indian/Mayotte" => "Africa/Nairobi",
Iran => "Asia/Tehran",
Israel => "Asia/Jerusalem",
Jamaica => "America/Jamaica",
Japan => "Asia/Tokyo",
Kwajalein => "Pacific/Kwajalein",
Libya => "Africa/Tripoli",
"Mexico/BajaNorte" => "America/Tijuana",
"Mexico/BajaSur" => "America/Mazatlan",
"Mexico/General" => "America/Mexico_City",
NZ => "Pacific/Auckland",
"NZ-CHAT" => "Pacific/Chatham",
Navajo => "America/Denver",
PRC => "Asia/Shanghai",
"Pacific/Johnston" => "Pacific/Honolulu",
"Pacific/Midway" => "Pacific/Pago_Pago",
"Pacific/Ponape" => "Pacific/Pohnpei",
"Pacific/Saipan" => "Pacific/Guam",
"Pacific/Samoa" => "Pacific/Pago_Pago",
"Pacific/Truk" => "Pacific/Chuuk",
"Pacific/Yap" => "Pacific/Chuuk",
Poland => "Europe/Warsaw",
Portugal => "Europe/Lisbon",
ROC => "Asia/Taipei",
ROK => "Asia/Seoul",
Singapore => "Asia/Singapore",
Turkey => "Europe/Istanbul",
UCT => "Etc/UCT",
"US/Alaska" => "America/Anchorage",
"US/Aleutian" => "America/Adak",
"US/Arizona" => "America/Phoenix",
"US/Central" => "America/Chicago",
"US/East-Indiana" => "America/Indiana/Indianapolis",
"US/Eastern" => "America/New_York",
"US/Hawaii" => "Pacific/Honolulu",
"US/Indiana-Starke" => "America/Indiana/Knox",
"US/Michigan" => "America/Detroit",
"US/Mountain" => "America/Denver",
"US/Pacific" => "America/Los_Angeles",
"US/Samoa" => "Pacific/Pago_Pago",
UTC => "Etc/UTC",
Universal => "Etc/UTC",
"W-SU" => "Europe/Moscow",
Zulu => "Etc/UTC",
});
sub olson_links() {
$li = eval($li) || die $@ if ref($li) eq "";
return $li;
}
=item olson_country_selection
Returns information about how timezones relate to countries, intended
to aid humans in selecting a geographical timezone. This information
is derived from the C<zone.tab> and C<iso3166.tab> files in the database
source.
The return value is a reference to a hash, keyed by (ISO 3166 alpha-2
uppercase) country code. The value for each country is a hash containing
these values:
=over
=item B<alpha2_code>
The ISO 3166 alpha-2 uppercase country code.
=item B<olson_name>
An English name for the country, possibly in a modified form, optimised
to help humans find the right entry in alphabetical lists. This is
not necessarily identical to the country's standard short or long name.
(For other forms of the name, consult a database of countries, keying
by the country code.)
=item B<regions>
Information about the regions of the country that use distinct
timezones. This is a hash, keyed by English description of the region.
The description is empty if there is only one region. The value for
each region is a hash containing these values:
=over
=item B<olson_description>
Brief English description of the region, used to distinguish between
the regions of a single country. Empty string if the country has only
one region for timezone purposes. (This is the same string used as the
key in the B<regions> hash.)
=item B<timezone_name>
Name of the Olson timezone used in this region. The named timezone is
guaranteed to exist in the database, but not necessarily as a canonical
name (it may be a link). Typically, where there are aliases or identical
canonical zones, a name is chosen that refers to a location in the
country of interest.
=item B<location_coords>
Geographical coordinates of some point within the location referred to in
the timezone name. This is a latitude and longitude, in ISO 6709 format.
=back
=back
This data structure is intended to help a human select the appropriate
timezone based on political geography, specifically working from a
selection of country. It is of essentially no use for any other purpose.
It is not strictly guaranteed that every geographical timezone in the
database is listed somewhere in this structure, so it is of limited use
in providing information about an already-selected timezone. It does
not include non-geographic timezones at all. It also does not claim
to be a comprehensive list of countries, and does not make any claims
regarding the political status of any entity listed: the "country"
classification is loose, and used only for identification purposes.
=cut
my $cs;
sub olson_country_selection() {
return $cs ||= do {
my $fn = _data_file("country_selection.tzp");
$@ = ""; do($fn) || die($@ eq "" ? "$fn: $!" : $@);
}
}
=back
=head2 Zone data
=over
=item olson_tzfile(NAME)
Returns the pathname of the binary tzfile (in L<tzfile(5)> format)
describing the timezone named I<NAME> in the Olson database. C<die>s if
the name does not exist in this version of the database. The tzfile
is of at least version 2 of the format, and so does not suffer a Y2038
(32-bit time_t) problem.
=cut
sub olson_tzfile($) {
my($tzname) = @_;
$tzname = olson_links()->{$tzname} if exists olson_links()->{$tzname};
unless(exists olson_canonical_names()->{$tzname}) {
require Carp;
Carp::croak("no such timezone `$tzname' ".
"in the Olson @{[olson_version]} database");
}
return _data_file($tzname.".tz");
}
=back
=head1 BUGS
The Olson timezone database probably contains errors in the older
historical data. These will be corrected, as they are discovered,
in future versions of the database.
Because legislatures commonly change civil timezone rules, in
unpredictable ways and often with little advance notice, the current
timezone data is liable to get out of date quite quickly. The Olson
timezone database is frequently updated to keep it accurate for current
dates. Frequently updating installations of this module from CPAN should
keep it similarly accurate.
For the same reason, the future data in the database is liable to be
very inaccurate. The database includes, for each timezone, the current
best guess regarding its future behaviour, usually consisting of the
current rules being left unchanged indefinitely. (In most cases it is
unlikely that the rules will actually never be changed, but the current
rules still constitute the best guess available of future behaviour.)
Because this module is intended to be frequently updated, long-running
programs (such as clock displays) will experience the module being
updated while in use. This can happen with any module, but is of
particular interest with this one. The behaviour in this situation is
not guaranteed, but here is a guide to current behaviour. The running
module code is of course not influenced by the C<.pm> file changing.
The ancillary data is all currently stored in the module code, and so
will be equally unaffected. Tzfiles pointed to by the module, however,
will change visibly. Newly reading a tzfile is liable to see a newer
version of the zone's data than the module's metadata suggests. A tzfile
could also theoretically disappear, if a zone's canonical name changes
(so the former canonical name becomes a link). To avoid weirdness,
it is recommended to read in all required tzfiles near the start of
a program's run, so that it doesn't matter if the files subsequently
change due to an update.
=head1 SEE ALSO
L<App::olson>,
L<DateTime::TimeZone::Olson>,
L<DateTime::TimeZone::Tzfile>,
L<Time::OlsonTZ::Download>,
L<tzfile(5)>
=head1 AUTHOR
The Olson timezone database was compiled by Arthur David Olson, Paul
Eggert, and many others. It is maintained by the denizens of the mailing
list <tz@iana.org> (formerly <tz@elsie.nci.nih.gov>).
The C<Time::OlsonTZ::Data> Perl module wrapper for the database was
developed by Andrew Main (Zefram) <zefram@fysh.org>.
=head1 COPYRIGHT
The Olson timezone database is is the public domain.
The C<Time::OlsonTZ::Data> Perl module wrapper for the database is
Copyright (C) 2010, 2011, 2012, 2013, 2014, 2017, 2018
Andrew Main (Zefram) <zefram@fysh.org>.
=head1 LICENSE
No license is required to do anything with public domain materials.
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
=cut
1;