On 2025-11-14 08:48, kirill.gagarski--- via tz wrote:
I noticed that zonedata now ships with zonenow.tab file which is exactly what
we need for our UI and meets our needs more precisely.
Unfortunately it seems quite impossible to migrate old data to this new
notation automatically. For example, hte fact that 'Europe/Berlin' is covered
by 'Europe/Paris' in zonenow.tab is not mentioned anywhere. Is there a way to
determine this fact from tzdata without deep analysis of the rules done by
myself?
checknow.awk already does that analysis. The attached proposed patch
causes it to put the zone equivalence class information into now.ck, if
you run the command 'make now.ck'. I'm attaching the resulting now.ck
that I just built that way. This is all a bit of a hack, but it was easy
for me to add and I hope it serves your purpose.
Other simple question: is there a way to know what is "now" in zonenow? Is it
defined by the release date of a new version?
That's the intent, yes. By default, "now" is when you run "make now.ck",
which is run as part of the release check process (see "make public"). I
suppose in theory this value of "now" could be far enough from the
release timestamp that zonenow.tab could be wrong for the release
timestamp, but this is so unlikely that I haven't worried about it: the
timestamps differ by at most a few minutes in practice, and if
zonenow.tab would mutate that soon in the future - something that has
never happened - I'd likely just wait a few minutes before releasing.
You can specify "now" by running "make CHECK_NOW_TIMESTAMP=$N now.ck",
where $N is the number of seconds since 1970, not counting leap seconds.
The now.ck file's first column specifies the value of "now" that was
used to build now.ck.From e3693aabeb7d4862f612d233a265c00095be15de Mon Sep 17 00:00:00 2001
From: Paul Eggert <[email protected]>
Date: Fri, 14 Nov 2025 10:04:01 -0800
Subject: [PROPOSED] Map zone1970 names to zonenow names
Requested by Kirill Gagarski in:
https://lists.iana.org/hyperkitty/list/[email protected]/thread/GI7TWK652BY6MOAE2YQLLCSDPTP7NSZC/
* Makefile (now.ck): Tell checknow.awk to put equivalence classes
from now on into now.ck.
* checknow.awk: Output equivalence classes if requested.
---
Makefile | 7 +++++--
checknow.awk | 5 +++++
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index 0d33fa17..bb7cb101 100644
--- a/Makefile
+++ b/Makefile
@@ -1026,8 +1026,10 @@ now.ck: checknow.awk date tzdata.zi zdump zic zone1970.tab zonenow.tab
./zdump -i -t 0,$$future \
$$(find "$$PWD/$@d" -name Etc -prune \
-o -type f ! -name '*.tab' -print) \
- >$@d/zdump-1970.tab
+ >$@d/zdump-1970.tab && \
$(AWK) \
+ -v now=$$now \
+ -v [email protected] \
-v zdump_table=$@d/zdump-now.tab \
-f checknow.awk zonenow.tab
$(AWK) \
@@ -1037,7 +1039,8 @@ now.ck: checknow.awk date tzdata.zi zdump zic zone1970.tab zonenow.tab
-v zdump_table=$@d/zdump-1970.tab \
-f checknow.awk
rm -fr $@d
- touch $@
+ touch [email protected]
+ mv [email protected] $@
tables.ck: checktab.awk $(YDATA) backward zone.tab zone1970.tab
for tab in $(ZONETABLES); do \
diff --git a/checknow.awk b/checknow.awk
index 450490ee..8139ad57 100644
--- a/checknow.awk
+++ b/checknow.awk
@@ -50,5 +50,10 @@ END {
status = 1
}
}
+ if (now_out) {
+ for (data in zones) {
+ printf "%s=%s\n", now, zones[data] >>now_out
+ }
+ }
exit status
}
--
2.51.0
1763143480= Asia/Rangoon Asia/Yangon Indian/Cocos
1763143480= America/Yellowknife America/Denver America/Cambridge_Bay
America/Ciudad_Juarez America/Shiprock America/Edmonton America/Boise
America/Inuvik Canada/Mountain
1763143480= Africa/Mogadishu Africa/Kampala Africa/Asmera Africa/Nairobi
Africa/Dar_es_Salaam Africa/Addis_Ababa Africa/Djibouti Africa/Asmara
Indian/Comoro Indian/Mayotte Indian/Antananarivo
1763143480= Africa/Brazzaville Africa/Kinshasa Africa/Bangui Africa/Libreville
Africa/Douala Africa/Lagos Africa/Niamey Africa/Ndjamena Africa/Malabo
Africa/Luanda Africa/Porto-Novo
1763143480= Europe/Dublin
1763143480= Europe/Volgograd Europe/Moscow Europe/Kirov Europe/Simferopol
1763143480= Australia/Eucla
1763143480= Atlantic/Azores
1763143480= Asia/Hebron Asia/Gaza
1763143480= Asia/Jakarta Asia/Pontianak
1763143480= Asia/Beirut
1763143480= Asia/Tokyo
1763143480= Africa/Ceuta Arctic/Longyearbyen Atlantic/Jan_Mayen Europe/Skopje
Europe/San_Marino Europe/Ljubljana Europe/Warsaw Europe/Sarajevo Europe/Zagreb
Europe/Vaduz Europe/Busingen Europe/Budapest Europe/Stockholm Europe/Amsterdam
Europe/Oslo Europe/Andorra Europe/Vatican Europe/Vienna Europe/Paris
Europe/Bratislava Europe/Luxembourg Europe/Madrid Europe/Rome Europe/Prague
Europe/Belgrade Europe/Malta Europe/Zurich Europe/Gibraltar Europe/Brussels
Europe/Copenhagen Europe/Tirane Europe/Podgorica Europe/Berlin Europe/Monaco
1763143480= Africa/Mbabane Africa/Johannesburg Africa/Maseru
1763143480= Pacific/Marquesas
1763143480= Pacific/Midway Pacific/Samoa Pacific/Pago_Pago
1763143480= Asia/Jayapura
1763143480= Antarctica/Syowa Asia/Amman Asia/Kuwait Asia/Istanbul Asia/Qatar
Asia/Bahrain Asia/Baghdad Asia/Damascus Asia/Riyadh Asia/Aden Europe/Minsk
Europe/Istanbul
1763143480= Africa/Cairo
1763143480= Asia/Tehran
1763143480= Asia/Yerevan Asia/Baku Asia/Muscat Asia/Tbilisi Asia/Dubai
Europe/Saratov Europe/Samara Europe/Astrakhan Europe/Ulyanovsk Indian/Mahe
Indian/Mauritius Indian/Reunion
1763143480= Asia/Kolkata Asia/Calcutta
1763143480= Africa/Tunis Africa/Algiers
1763143480= Pacific/Chatham
1763143480= Pacific/Guam Pacific/Saipan
1763143480= Australia/Lord_Howe Australia/LHI
1763143480= Atlantic/Cape_Verde
1763143480= Asia/Ujung_Pandang Asia/Makassar
1763143480= Asia/Katmandu Asia/Kathmandu
1763143480= Antarctica/DumontDUrville Asia/Vladivostok Asia/Ust-Nera
Pacific/Yap Pacific/Chuuk Pacific/Port_Moresby Pacific/Truk
1763143480= Antarctica/South_Pole Antarctica/McMurdo Pacific/Auckland
1763143480= Antarctica/Mawson Antarctica/Vostok Asia/Atyrau Asia/Oral
Asia/Dushanbe Asia/Samarkand Asia/Yekaterinburg Asia/Almaty Asia/Qostanay
Asia/Ashgabat Asia/Tashkent Asia/Aqtau Asia/Ashkhabad Asia/Aqtobe
Asia/Qyzylorda Indian/Maldives Indian/Kerguelen
1763143480= America/Goose_Bay America/Thule America/Moncton America/Halifax
America/Glace_Bay Atlantic/Bermuda Canada/Atlantic
1763143480= America/Indianapolis America/Iqaluit America/Pangnirtung
America/Fort_Wayne America/Thunder_Bay America/New_York America/Detroit
America/Nassau America/Grand_Turk America/Nipigon America/Indiana/Petersburg
America/Indiana/Vevay America/Indiana/Marengo America/Indiana/Indianapolis
America/Indiana/Winamac America/Indiana/Vincennes America/Montreal
America/Port-au-Prince America/Toronto America/Kentucky/Monticello
America/Kentucky/Louisville America/Louisville Canada/Eastern
1763143480= Pacific/Norfolk
1763143480= Europe/Tiraspol Europe/Chisinau
1763143480= Australia/South Australia/Yancowinna Australia/Adelaide
Australia/Broken_Hill
1763143480= Asia/Kabul
1763143480= Asia/Sakhalin Asia/Srednekolymsk Asia/Magadan Pacific/Guadalcanal
Pacific/Noumea Pacific/Ponape Pacific/Bougainville Pacific/Efate Pacific/Kosrae
Pacific/Pohnpei
1763143480= Asia/Kashgar Asia/Dhaka Asia/Urumqi Asia/Omsk Asia/Dacca
Asia/Thimbu Asia/Thimphu Asia/Bishkek Indian/Chagos
1763143480= America/Noronha Atlantic/South_Georgia Brazil/DeNoronha
1763143480= Africa/Conakry Africa/Timbuktu Africa/Freetown Africa/Ouagadougou
Africa/Sao_Tome Africa/Lome Africa/Monrovia Africa/Bamako Africa/Accra
Africa/Banjul Africa/Dakar Africa/Bissau Africa/Nouakchott Africa/Abidjan
America/Danmarkshavn Atlantic/St_Helena Atlantic/Reykjavik
1763143480= Australia/Darwin Australia/North
1763143480= Australia/West Australia/Perth
1763143480= Atlantic/Faeroe Atlantic/Madeira Atlantic/Canary Atlantic/Faroe
Europe/Lisbon
1763143480= Asia/Manila
1763143480= Asia/Kamchatka Asia/Anadyr Pacific/Wake Pacific/Nauru
Pacific/Kwajalein Pacific/Funafuti Pacific/Fiji Pacific/Majuro Pacific/Tarawa
Pacific/Wallis
1763143480= Antarctica/Davis Asia/Vientiane Asia/Ho_Chi_Minh Asia/Saigon
Asia/Novosibirsk Asia/Tomsk Asia/Phnom_Penh Asia/Bangkok Asia/Krasnoyarsk
Asia/Novokuznetsk Asia/Hovd Asia/Barnaul Indian/Christmas
1763143480= Antarctica/Macquarie Australia/Sydney Australia/Tasmania
Australia/ACT Australia/Hobart Australia/Currie Australia/Canberra
Australia/Victoria Australia/NSW Australia/Melbourne
1763143480= America/Vancouver America/Tijuana America/Los_Angeles
America/Ensenada America/Santa_Isabel Canada/Pacific Mexico/BajaNorte
1763143480= America/Rosario America/Araguaina America/Argentina/Rio_Gallegos
America/Argentina/Cordoba America/Argentina/Ushuaia America/Argentina/Salta
America/Argentina/Tucuman America/Argentina/Buenos_Aires
America/Argentina/La_Rioja America/Argentina/Mendoza
America/Argentina/Catamarca America/Argentina/San_Juan
America/Argentina/ComodRivadavia America/Argentina/San_Luis
America/Argentina/Jujuy America/Punta_Arenas America/Asuncion America/Coyhaique
America/Maceio America/Montevideo America/Belem America/Cordoba
America/Paramaribo America/Bahia America/Fortaleza America/Cayenne
America/Recife America/Santarem America/Jujuy America/Catamarca
America/Sao_Paulo America/Buenos_Aires America/Mendoza Antarctica/Palmer
Antarctica/Rothera Atlantic/Stanley Brazil/East
1763143480= Pacific/Enderbury Pacific/Kanton Pacific/Fakaofo Pacific/Apia
Pacific/Tongatapu
1763143480= Europe/London Europe/Jersey Europe/Guernsey Europe/Belfast
Europe/Isle_of_Man
1763143480= Asia/Colombo
1763143480= Asia/Pyongyang Asia/Seoul
1763143480= Antarctica/Troll
1763143480= Antarctica/Casey Asia/Kuala_Lumpur Asia/Ulaanbaatar Asia/Brunei
Asia/Singapore Asia/Irkutsk Asia/Choibalsan Asia/Ulan_Bator Asia/Kuching
1763143480= America/Atka America/Adak
1763143480= America/Juneau America/Sitka America/Yakutat America/Nome
America/Anchorage America/Metlakatla
1763143480= America/Miquelon
1763143480= America/Caracas America/Campo_Grande America/Manaus
America/Porto_Velho America/Boa_Vista America/Cuiaba America/Guyana
America/La_Paz Brazil/West
1763143480= Pacific/Kiritimati
1763143480= Pacific/Rarotonga Pacific/Tahiti
1763143480= Chile/EasterIsland Pacific/Easter
1763143480= Asia/Dili Asia/Chita Asia/Khandyga Asia/Yakutsk Pacific/Palau
1763143480= America/Jamaica America/Coral_Harbour America/Panama
America/Atikokan America/Cancun America/Cayman
1763143480= America/Rio_Branco America/Lima America/Porto_Acre America/Eirunepe
America/Bogota America/Guayaquil Brazil/Acre
1763143480= Pacific/Niue
1763143480= Pacific/Galapagos
1763143480= Pacific/Honolulu Pacific/Johnston
1763143480= Asia/Famagusta Asia/Nicosia Europe/Athens Europe/Uzhgorod
Europe/Nicosia Europe/Bucharest Europe/Mariehamn Europe/Sofia Europe/Tallinn
Europe/Vilnius Europe/Kyiv Europe/Kiev Europe/Zaporozhye Europe/Helsinki
Europe/Riga
1763143480= America/North_Dakota/Center America/North_Dakota/New_Salem
America/North_Dakota/Beulah America/Resolute America/Menominee America/Knox_IN
America/Chicago America/Indiana/Knox America/Indiana/Tell_City
America/Rainy_River America/Ojinaga America/Rankin_Inlet America/Winnipeg
America/Matamoros Canada/Central
1763143480= Africa/Tripoli Europe/Kaliningrad
1763143480= Asia/Jerusalem Asia/Tel_Aviv
1763143480= America/Godthab America/Nuuk America/Scoresbysund
1763143480= Africa/El_Aaiun Africa/Casablanca
1763143480= Pacific/Pitcairn
1763143480= Australia/Queensland Australia/Lindeman Australia/Brisbane
1763143480= Asia/Karachi
1763143480= Asia/Hong_Kong
1763143480= Asia/Chongqing Asia/Macau Asia/Taipei Asia/Macao Asia/Harbin
Asia/Chungking Asia/Shanghai
1763143480= America/Chihuahua America/Guatemala America/Monterrey
America/Tegucigalpa America/Merida America/Swift_Current America/El_Salvador
America/Mexico_City America/Managua America/Bahia_Banderas America/Belize
America/Regina America/Costa_Rica Canada/Saskatchewan Mexico/General
1763143480= America/Fort_Nelson America/Hermosillo America/Whitehorse
America/Mazatlan America/Dawson_Creek America/Creston America/Phoenix
America/Dawson Canada/Yukon Mexico/BajaSur
1763143480= America/Grenada America/Marigot America/St_Thomas
America/Martinique America/Lower_Princes America/Anguilla America/Tortola
America/Virgin America/St_Kitts America/Santo_Domingo America/Montserrat
America/Puerto_Rico America/St_Barthelemy America/St_Vincent America/Curacao
America/Aruba America/Port_of_Spain America/Kralendijk America/Barbados
America/Guadeloupe America/St_Lucia America/Blanc-Sablon America/Dominica
America/Antigua
1763143480= Africa/Bujumbura Africa/Maputo Africa/Harare Africa/Kigali
Africa/Khartoum Africa/Lubumbashi Africa/Lusaka Africa/Blantyre Africa/Windhoek
Africa/Juba Africa/Gaborone
1763143480= Pacific/Gambier
1763143480= America/Santiago Chile/Continental
1763143480= America/Havana
1763143480= America/St_Johns Canada/Newfoundland
