From 70f2e59f68a35b82e2e2f4806d45200e3eac9136 Mon Sep 17 00:00:00 2001
From: labmecanicatec <58854556+labmecanicatec@users.noreply.github.com>
Date: Wed, 30 Jul 2025 09:53:55 -0500
Subject: [PATCH] refactor: timezone handling and remove jstz library

Replaced the manual timezone list in config/timezones.php with dynamic generation using DateTimeZone::listIdentifiers(). Removed the jstz.min.js library and updated register.tpl to use the native Intl.DateTimeFormat API for timezone detection, simplifying the code and reducing dependencies.
---
 Web/scripts/js/jstz.min.js |  13 --
 config/timezones.php       | 409 +------------------------------------
 tpl/register.tpl           |   9 +-
 3 files changed, 5 insertions(+), 426 deletions(-)
 delete mode 100644 Web/scripts/js/jstz.min.js

diff --git a/Web/scripts/js/jstz.min.js b/Web/scripts/js/jstz.min.js
deleted file mode 100644
index 0c12c4e9d..000000000
--- a/Web/scripts/js/jstz.min.js
+++ /dev/null
@@ -1,13 +0,0 @@
-var jstz=function(){var b=function(a){a=-a.getTimezoneOffset();return a!==null?a:0},d=function(){return b(new Date(2010,0,1,0,0,0,0))},e=function(){return b(new Date(2010,5,1,0,0,0,0))},c=function(){var a=d(),b=e(),f=d()-e();if(f<0)return a+",1";else if(f>0)return b+",1,s";return a+",0"};return{determine_timezone:function(){var a=c();return new jstz.TimeZone(jstz.olson.timezones[a])},date_is_dst:function(a){var c=a.getMonth()>5?e():d(),a=b(a);return c-a!==0}}}();
-jstz.TimeZone=function(){var b=null,d=null,e=null,c=function(a){e=a[0];b=a[1];d=a[2];if(typeof jstz.olson.ambiguity_list[b]!=="undefined")for(var a=jstz.olson.ambiguity_list[b],c=a.length,f=0,g=a[0];f<c;f+=1)if(g=a[f],jstz.date_is_dst(jstz.olson.dst_start_dates[g])){b=g;break}};c.prototype={constructor:jstz.TimeZone,name:function(){return b},dst:function(){return d},offset:function(){return e}};return c}();jstz.olson={};
-jstz.olson.timezones=function(){return{"-720,0":["-12:00","Etc/GMT+12",!1],"-660,0":["-11:00","Pacific/Pago_Pago",!1],"-600,1":["-11:00","America/Adak",!0],"-660,1,s":["-11:00","Pacific/Apia",!0],"-600,0":["-10:00","Pacific/Honolulu",!1],"-570,0":["-09:30","Pacific/Marquesas",!1],"-540,0":["-09:00","Pacific/Gambier",!1],"-540,1":["-09:00","America/Anchorage",!0],"-480,1":["-08:00","America/Los_Angeles",!0],"-480,0":["-08:00","Pacific/Pitcairn",!1],"-420,0":["-07:00","America/Phoenix",!1],"-420,1":["-07:00",
-"America/Denver",!0],"-360,0":["-06:00","America/Guatemala",!1],"-360,1":["-06:00","America/Chicago",!0],"-360,1,s":["-06:00","Pacific/Easter",!0],"-300,0":["-05:00","America/Bogota",!1],"-300,1":["-05:00","America/New_York",!0],"-270,0":["-04:30","America/Caracas",!1],"-240,1":["-04:00","America/Halifax",!0],"-240,0":["-04:00","America/Santo_Domingo",!1],"-240,1,s":["-04:00","America/Asuncion",!0],"-210,1":["-03:30","America/St_Johns",!0],"-180,1":["-03:00","America/Godthab",!0],"-180,0":["-03:00",
-"America/Argentina/Buenos_Aires",!1],"-180,1,s":["-03:00","America/Montevideo",!0],"-120,0":["-02:00","America/Noronha",!1],"-120,1":["-02:00","Etc/GMT+2",!0],"-60,1":["-01:00","Atlantic/Azores",!0],"-60,0":["-01:00","Atlantic/Cape_Verde",!1],"0,0":["00:00","Etc/UTC",!1],"0,1":["00:00","Europe/London",!0],"60,1":["+01:00","Europe/Berlin",!0],"60,0":["+01:00","Africa/Lagos",!1],"60,1,s":["+01:00","Africa/Windhoek",!0],"120,1":["+02:00","Asia/Beirut",!0],"120,0":["+02:00","Africa/Johannesburg",!1],
-"180,1":["+03:00","Europe/Moscow",!0],"180,0":["+03:00","Asia/Baghdad",!1],"210,1":["+03:30","Asia/Tehran",!0],"240,0":["+04:00","Asia/Dubai",!1],"240,1":["+04:00","Asia/Yerevan",!0],"270,0":["+04:30","Asia/Kabul",!1],"300,1":["+05:00","Asia/Yekaterinburg",!0],"300,0":["+05:00","Asia/Karachi",!1],"330,0":["+05:30","Asia/Kolkata",!1],"345,0":["+05:45","Asia/Kathmandu",!1],"360,0":["+06:00","Asia/Dhaka",!1],"360,1":["+06:00","Asia/Omsk",!0],"390,0":["+06:30","Asia/Rangoon",!1],"420,1":["+07:00","Asia/Krasnoyarsk",
-!0],"420,0":["+07:00","Asia/Jakarta",!1],"480,0":["+08:00","Asia/Shanghai",!1],"480,1":["+08:00","Asia/Irkutsk",!0],"525,0":["+08:45","Australia/Eucla",!0],"525,1,s":["+08:45","Australia/Eucla",!0],"540,1":["+09:00","Asia/Yakutsk",!0],"540,0":["+09:00","Asia/Tokyo",!1],"570,0":["+09:30","Australia/Darwin",!1],"570,1,s":["+09:30","Australia/Adelaide",!0],"600,0":["+10:00","Australia/Brisbane",!1],"600,1":["+10:00","Asia/Vladivostok",!0],"600,1,s":["+10:00","Australia/Sydney",!0],"630,1,s":["+10:30",
-"Australia/Lord_Howe",!0],"660,1":["+11:00","Asia/Kamchatka",!0],"660,0":["+11:00","Pacific/Noumea",!1],"690,0":["+11:30","Pacific/Norfolk",!1],"720,1,s":["+12:00","Pacific/Auckland",!0],"720,0":["+12:00","Pacific/Tarawa",!1],"765,1,s":["+12:45","Pacific/Chatham",!0],"780,0":["+13:00","Pacific/Tongatapu",!1],"840,0":["+14:00","Pacific/Kiritimati",!1]}}();
-jstz.olson.dst_start_dates=function(){return{"America/Denver":new Date(2011,2,13,3,0,0,0),"America/Mazatlan":new Date(2011,3,3,3,0,0,0),"America/Chicago":new Date(2011,2,13,3,0,0,0),"America/Mexico_City":new Date(2011,3,3,3,0,0,0),"Atlantic/Stanley":new Date(2011,8,4,7,0,0,0),"America/Asuncion":new Date(2011,9,2,3,0,0,0),"America/Santiago":new Date(2011,9,9,3,0,0,0),"America/Campo_Grande":new Date(2011,9,16,5,0,0,0),"America/Montevideo":new Date(2011,9,2,3,0,0,0),"America/Sao_Paulo":new Date(2011,
-9,16,5,0,0,0),"America/Los_Angeles":new Date(2011,2,13,8,0,0,0),"America/Santa_Isabel":new Date(2011,3,5,8,0,0,0),"America/Havana":new Date(2011,2,13,2,0,0,0),"America/New_York":new Date(2011,2,13,7,0,0,0),"Asia/Gaza":new Date(2011,2,26,23,0,0,0),"Asia/Beirut":new Date(2011,2,27,1,0,0,0),"Europe/Minsk":new Date(2011,2,27,2,0,0,0),"Europe/Helsinki":new Date(2011,2,27,4,0,0,0),"Europe/Istanbul":new Date(2011,2,28,5,0,0,0),"Asia/Damascus":new Date(2011,3,1,2,0,0,0),"Asia/Jerusalem":new Date(2011,3,1,
-6,0,0,0),"Africa/Cairo":new Date(2010,3,30,4,0,0,0),"Asia/Yerevan":new Date(2011,2,27,4,0,0,0),"Asia/Baku":new Date(2011,2,27,8,0,0,0),"Pacific/Auckland":new Date(2011,8,26,7,0,0,0),"Pacific/Fiji":new Date(2010,11,29,23,0,0,0),"America/Halifax":new Date(2011,2,13,6,0,0,0),"America/Goose_Bay":new Date(2011,2,13,2,1,0,0),"America/Miquelon":new Date(2011,2,13,5,0,0,0),"America/Godthab":new Date(2011,2,27,1,0,0,0)}}();
-jstz.olson.ambiguity_list={"America/Denver":["America/Denver","America/Mazatlan"],"America/Chicago":["America/Chicago","America/Mexico_City"],"America/Asuncion":["Atlantic/Stanley","America/Asuncion","America/Santiago","America/Campo_Grande"],"America/Montevideo":["America/Montevideo","America/Sao_Paulo"],"Asia/Beirut":"Asia/Gaza,Asia/Beirut,Europe/Minsk,Europe/Helsinki,Europe/Istanbul,Asia/Damascus,Asia/Jerusalem,Africa/Cairo".split(","),"Asia/Yerevan":["Asia/Yerevan","Asia/Baku"],"Pacific/Auckland":["Pacific/Auckland",
-"Pacific/Fiji"],"America/Los_Angeles":["America/Los_Angeles","America/Santa_Isabel"],"America/New_York":["America/Havana","America/New_York"],"America/Halifax":["America/Goose_Bay","America/Halifax"],"America/Godthab":["America/Miquelon","America/Godthab"]};
\ No newline at end of file
diff --git a/config/timezones.php b/config/timezones.php
index 1cb67352e..7d1862102 100644
--- a/config/timezones.php
+++ b/config/timezones.php
@@ -1,411 +1,8 @@
 <?php
 
-AddTimezone('Africa/Abidjan');
-AddTimezone('Africa/Accra');
-AddTimezone('Africa/Addis_Ababa');
-AddTimezone('Africa/Algiers');
-AddTimezone('Africa/Asmara');
-AddTimezone('Africa/Bamako');
-AddTimezone('Africa/Bangui');
-AddTimezone('Africa/Banjul');
-AddTimezone('Africa/Bissau');
-AddTimezone('Africa/Blantyre');
-AddTimezone('Africa/Brazzaville');
-AddTimezone('Africa/Bujumbura');
-AddTimezone('Africa/Cairo');
-AddTimezone('Africa/Casablanca');
-AddTimezone('Africa/Ceuta');
-AddTimezone('Africa/Conakry');
-AddTimezone('Africa/Dakar');
-AddTimezone('Africa/Dar_es_Salaam');
-AddTimezone('Africa/Djibouti');
-AddTimezone('Africa/Douala');
-AddTimezone('Africa/El_Aaiun');
-AddTimezone('Africa/Freetown');
-AddTimezone('Africa/Gaborone');
-AddTimezone('Africa/Harare');
-AddTimezone('Africa/Johannesburg');
-AddTimezone('Africa/Kampala');
-AddTimezone('Africa/Khartoum');
-AddTimezone('Africa/Kigali');
-AddTimezone('Africa/Kinshasa');
-AddTimezone('Africa/Lagos');
-AddTimezone('Africa/Libreville');
-AddTimezone('Africa/Lome');
-AddTimezone('Africa/Luanda');
-AddTimezone('Africa/Lubumbashi');
-AddTimezone('Africa/Lusaka');
-AddTimezone('Africa/Malabo');
-AddTimezone('Africa/Maputo');
-AddTimezone('Africa/Maseru');
-AddTimezone('Africa/Mbabane');
-AddTimezone('Africa/Mogadishu');
-AddTimezone('Africa/Monrovia');
-AddTimezone('Africa/Nairobi');
-AddTimezone('Africa/Ndjamena');
-AddTimezone('Africa/Niamey');
-AddTimezone('Africa/Nouakchott');
-AddTimezone('Africa/Ouagadougou');
-AddTimezone('Africa/Porto-Novo');
-AddTimezone('Africa/Sao_Tome');
-AddTimezone('Africa/Tripoli');
-AddTimezone('Africa/Tunis');
-AddTimezone('Africa/Windhoek');
-AddTimezone('America/Adak');
-AddTimezone('America/Anchorage');
-AddTimezone('America/Anguilla');
-AddTimezone('America/Antigua');
-AddTimezone('America/Araguaina');
-AddTimezone('America/Argentina/Buenos_Aires');
-AddTimezone('America/Argentina/Catamarca');
-AddTimezone('America/Argentina/Cordoba');
-AddTimezone('America/Argentina/Jujuy');
-AddTimezone('America/Argentina/La_Rioja');
-AddTimezone('America/Argentina/Mendoza');
-AddTimezone('America/Argentina/Rio_Gallegos');
-AddTimezone('America/Argentina/Salta');
-AddTimezone('America/Argentina/San_Juan');
-AddTimezone('America/Argentina/San_Luis');
-AddTimezone('America/Argentina/Tucuman');
-AddTimezone('America/Argentina/Ushuaia');
-AddTimezone('America/Aruba');
-AddTimezone('America/Asuncion');
-AddTimezone('America/Atikokan');
-AddTimezone('America/Bahia');
-AddTimezone('America/Barbados');
-AddTimezone('America/Belem');
-AddTimezone('America/Belize');
-AddTimezone('America/Blanc-Sablon');
-AddTimezone('America/Boa_Vista');
-AddTimezone('America/Bogota');
-AddTimezone('America/Boise');
-AddTimezone('America/Cambridge_Bay');
-AddTimezone('America/Campo_Grande');
-AddTimezone('America/Cancun');
-AddTimezone('America/Caracas');
-AddTimezone('America/Cayenne');
-AddTimezone('America/Cayman');
-AddTimezone('America/Chicago');
-AddTimezone('America/Chihuahua');
-AddTimezone('America/Costa_Rica');
-AddTimezone('America/Cuiaba');
-AddTimezone('America/Curacao');
-AddTimezone('America/Danmarkshavn');
-AddTimezone('America/Dawson');
-AddTimezone('America/Dawson_Creek');
-AddTimezone('America/Denver');
-AddTimezone('America/Detroit');
-AddTimezone('America/Dominica');
-AddTimezone('America/Edmonton');
-AddTimezone('America/Eirunepe');
-AddTimezone('America/El_Salvador');
-AddTimezone('America/Fortaleza');
-AddTimezone('America/Glace_Bay');
-AddTimezone('America/Godthab');
-AddTimezone('America/Goose_Bay');
-AddTimezone('America/Grand_Turk');
-AddTimezone('America/Grenada');
-AddTimezone('America/Guadeloupe');
-AddTimezone('America/Guatemala');
-AddTimezone('America/Guayaquil');
-AddTimezone('America/Guyana');
-AddTimezone('America/Halifax');
-AddTimezone('America/Havana');
-AddTimezone('America/Hermosillo');
-AddTimezone('America/Indiana/Indianapolis');
-AddTimezone('America/Indiana/Knox');
-AddTimezone('America/Indiana/Marengo');
-AddTimezone('America/Indiana/Petersburg');
-AddTimezone('America/Indiana/Tell_City');
-AddTimezone('America/Indiana/Vevay');
-AddTimezone('America/Indiana/Vincennes');
-AddTimezone('America/Indiana/Winamac');
-AddTimezone('America/Inuvik');
-AddTimezone('America/Iqaluit');
-AddTimezone('America/Jamaica');
-AddTimezone('America/Juneau');
-AddTimezone('America/Kentucky/Louisville');
-AddTimezone('America/Kentucky/Monticello');
-AddTimezone('America/La_Paz');
-AddTimezone('America/Lima');
-AddTimezone('America/Los_Angeles');
-AddTimezone('America/Maceio');
-AddTimezone('America/Managua');
-AddTimezone('America/Manaus');
-AddTimezone('America/Marigot');
-AddTimezone('America/Martinique');
-AddTimezone('America/Matamoros');
-AddTimezone('America/Mazatlan');
-AddTimezone('America/Menominee');
-AddTimezone('America/Merida');
-AddTimezone('America/Mexico_City');
-AddTimezone('America/Miquelon');
-AddTimezone('America/Moncton');
-AddTimezone('America/Monterrey');
-AddTimezone('America/Montevideo');
-AddTimezone('America/Montreal');
-AddTimezone('America/Montserrat');
-AddTimezone('America/Nassau');
-AddTimezone('America/New_York');
-AddTimezone('America/Nipigon');
-AddTimezone('America/Nome');
-AddTimezone('America/Noronha');
-AddTimezone('America/North_Dakota/Center');
-AddTimezone('America/North_Dakota/New_Salem');
-AddTimezone('America/Ojinaga');
-AddTimezone('America/Panama');
-AddTimezone('America/Pangnirtung');
-AddTimezone('America/Paramaribo');
-AddTimezone('America/Phoenix');
-AddTimezone('America/Port-au-Prince');
-AddTimezone('America/Port_of_Spain');
-AddTimezone('America/Porto_Velho');
-AddTimezone('America/Puerto_Rico');
-AddTimezone('America/Rainy_River');
-AddTimezone('America/Rankin_Inlet');
-AddTimezone('America/Recife');
-AddTimezone('America/Regina');
-AddTimezone('America/Resolute');
-AddTimezone('America/Rio_Branco');
-AddTimezone('America/Santa_Isabel');
-AddTimezone('America/Santarem');
-AddTimezone('America/Santiago');
-AddTimezone('America/Santo_Domingo');
-AddTimezone('America/Sao_Paulo');
-AddTimezone('America/Scoresbysund');
-AddTimezone('America/Shiprock');
-AddTimezone('America/St_Barthelemy');
-AddTimezone('America/St_Johns');
-AddTimezone('America/St_Kitts');
-AddTimezone('America/St_Lucia');
-AddTimezone('America/St_Thomas');
-AddTimezone('America/St_Vincent');
-AddTimezone('America/Swift_Current');
-AddTimezone('America/Tegucigalpa');
-AddTimezone('America/Thule');
-AddTimezone('America/Thunder_Bay');
-AddTimezone('America/Tijuana');
-AddTimezone('America/Toronto');
-AddTimezone('America/Tortola');
-AddTimezone('America/Vancouver');
-AddTimezone('America/Whitehorse');
-AddTimezone('America/Winnipeg');
-AddTimezone('America/Yakutat');
-AddTimezone('America/Yellowknife');
-AddTimezone('Antarctica/Casey');
-AddTimezone('Antarctica/Davis');
-AddTimezone('Antarctica/DumontDUrville');
-AddTimezone('Antarctica/Mawson');
-AddTimezone('Antarctica/McMurdo');
-AddTimezone('Antarctica/Palmer');
-AddTimezone('Antarctica/Rothera');
-AddTimezone('Antarctica/South_Pole');
-AddTimezone('Antarctica/Syowa');
-AddTimezone('Antarctica/Vostok');
-AddTimezone('Arctic/Longyearbyen');
-AddTimezone('Asia/Aden');
-AddTimezone('Asia/Almaty');
-AddTimezone('Asia/Amman');
-AddTimezone('Asia/Anadyr');
-AddTimezone('Asia/Aqtau');
-AddTimezone('Asia/Aqtobe');
-AddTimezone('Asia/Ashgabat');
-AddTimezone('Asia/Baghdad');
-AddTimezone('Asia/Bahrain');
-AddTimezone('Asia/Baku');
-AddTimezone('Asia/Bangkok');
-AddTimezone('Asia/Beirut');
-AddTimezone('Asia/Bishkek');
-AddTimezone('Asia/Brunei');
-AddTimezone('Asia/Choibalsan');
-AddTimezone('Asia/Chongqing');
-AddTimezone('Asia/Colombo');
-AddTimezone('Asia/Damascus');
-AddTimezone('Asia/Dhaka');
-AddTimezone('Asia/Dili');
-AddTimezone('Asia/Dubai');
-AddTimezone('Asia/Dushanbe');
-AddTimezone('Asia/Gaza');
-AddTimezone('Asia/Harbin');
-AddTimezone('Asia/Ho_Chi_Minh');
-AddTimezone('Asia/Hong_Kong');
-AddTimezone('Asia/Hovd');
-AddTimezone('Asia/Irkutsk');
-AddTimezone('Asia/Jakarta');
-AddTimezone('Asia/Jayapura');
-AddTimezone('Asia/Jerusalem');
-AddTimezone('Asia/Kabul');
-AddTimezone('Asia/Kamchatka');
-AddTimezone('Asia/Karachi');
-AddTimezone('Asia/Kashgar');
-AddTimezone('Asia/Kathmandu');
-AddTimezone('Asia/Kolkata');
-AddTimezone('Asia/Krasnoyarsk');
-AddTimezone('Asia/Kuala_Lumpur');
-AddTimezone('Asia/Kuching');
-AddTimezone('Asia/Kuwait');
-AddTimezone('Asia/Macau');
-AddTimezone('Asia/Magadan');
-AddTimezone('Asia/Makassar');
-AddTimezone('Asia/Manila');
-AddTimezone('Asia/Muscat');
-AddTimezone('Asia/Nicosia');
-AddTimezone('Asia/Novokuznetsk');
-AddTimezone('Asia/Novosibirsk');
-AddTimezone('Asia/Omsk');
-AddTimezone('Asia/Oral');
-AddTimezone('Asia/Phnom_Penh');
-AddTimezone('Asia/Pontianak');
-AddTimezone('Asia/Pyongyang');
-AddTimezone('Asia/Qatar');
-AddTimezone('Asia/Qyzylorda');
-AddTimezone('Asia/Rangoon');
-AddTimezone('Asia/Riyadh');
-AddTimezone('Asia/Sakhalin');
-AddTimezone('Asia/Samarkand');
-AddTimezone('Asia/Seoul');
-AddTimezone('Asia/Shanghai');
-AddTimezone('Asia/Singapore');
-AddTimezone('Asia/Taipei');
-AddTimezone('Asia/Tashkent');
-AddTimezone('Asia/Tbilisi');
-AddTimezone('Asia/Tehran');
-AddTimezone('Asia/Thimphu');
-AddTimezone('Asia/Tokyo');
-AddTimezone('Asia/Ulaanbaatar');
-AddTimezone('Asia/Urumqi');
-AddTimezone('Asia/Vientiane');
-AddTimezone('Asia/Vladivostok');
-AddTimezone('Asia/Yakutsk');
-AddTimezone('Asia/Yekaterinburg');
-AddTimezone('Asia/Yerevan');
-AddTimezone('Atlantic/Azores');
-AddTimezone('Atlantic/Bermuda');
-AddTimezone('Atlantic/Canary');
-AddTimezone('Atlantic/Cape_Verde');
-AddTimezone('Atlantic/Faroe');
-AddTimezone('Atlantic/Madeira');
-AddTimezone('Atlantic/Reykjavik');
-AddTimezone('Atlantic/South_Georgia');
-AddTimezone('Atlantic/St_Helena');
-AddTimezone('Atlantic/Stanley');
-AddTimezone('Australia/Adelaide');
-AddTimezone('Australia/Brisbane');
-AddTimezone('Australia/Broken_Hill');
-AddTimezone('Australia/Currie');
-AddTimezone('Australia/Darwin');
-AddTimezone('Australia/Eucla');
-AddTimezone('Australia/Hobart');
-AddTimezone('Australia/Lindeman');
-AddTimezone('Australia/Lord_Howe');
-AddTimezone('Australia/Melbourne');
-AddTimezone('Australia/Perth');
-AddTimezone('Australia/Sydney');
-AddTimezone('Europe/Amsterdam');
-AddTimezone('Europe/Andorra');
-AddTimezone('Europe/Athens');
-AddTimezone('Europe/Belgrade');
-AddTimezone('Europe/Berlin');
-AddTimezone('Europe/Bratislava');
-AddTimezone('Europe/Brussels');
-AddTimezone('Europe/Bucharest');
-AddTimezone('Europe/Budapest');
-AddTimezone('Europe/Chisinau');
-AddTimezone('Europe/Copenhagen');
-AddTimezone('Europe/Dublin');
-AddTimezone('Europe/Gibraltar');
-AddTimezone('Europe/Guernsey');
-AddTimezone('Europe/Helsinki');
-AddTimezone('Europe/Isle_of_Man');
-AddTimezone('Europe/Istanbul');
-AddTimezone('Europe/Jersey');
-AddTimezone('Europe/Kaliningrad');
-AddTimezone('Europe/Kiev');
-AddTimezone('Europe/Lisbon');
-AddTimezone('Europe/Ljubljana');
-AddTimezone('Europe/London');
-AddTimezone('Europe/Luxembourg');
-AddTimezone('Europe/Madrid');
-AddTimezone('Europe/Malta');
-AddTimezone('Europe/Mariehamn');
-AddTimezone('Europe/Minsk');
-AddTimezone('Europe/Monaco');
-AddTimezone('Europe/Moscow');
-AddTimezone('Europe/Oslo');
-AddTimezone('Europe/Paris');
-AddTimezone('Europe/Podgorica');
-AddTimezone('Europe/Prague');
-AddTimezone('Europe/Riga');
-AddTimezone('Europe/Rome');
-AddTimezone('Europe/Samara');
-AddTimezone('Europe/San_Marino');
-AddTimezone('Europe/Sarajevo');
-AddTimezone('Europe/Simferopol');
-AddTimezone('Europe/Skopje');
-AddTimezone('Europe/Sofia');
-AddTimezone('Europe/Stockholm');
-AddTimezone('Europe/Tallinn');
-AddTimezone('Europe/Tirane');
-AddTimezone('Europe/Uzhgorod');
-AddTimezone('Europe/Vaduz');
-AddTimezone('Europe/Vatican');
-AddTimezone('Europe/Vienna');
-AddTimezone('Europe/Vilnius');
-AddTimezone('Europe/Volgograd');
-AddTimezone('Europe/Warsaw');
-AddTimezone('Europe/Zagreb');
-AddTimezone('Europe/Zaporozhye');
-AddTimezone('Europe/Zurich');
-AddTimezone('Indian/Antananarivo');
-AddTimezone('Indian/Chagos');
-AddTimezone('Indian/Christmas');
-AddTimezone('Indian/Cocos');
-AddTimezone('Indian/Comoro');
-AddTimezone('Indian/Kerguelen');
-AddTimezone('Indian/Mahe');
-AddTimezone('Indian/Maldives');
-AddTimezone('Indian/Mauritius');
-AddTimezone('Indian/Mayotte');
-AddTimezone('Indian/Reunion');
-AddTimezone('Pacific/Apia');
-AddTimezone('Pacific/Auckland');
-AddTimezone('Pacific/Chatham');
-AddTimezone('Pacific/Easter');
-AddTimezone('Pacific/Efate');
-AddTimezone('Pacific/Enderbury');
-AddTimezone('Pacific/Fakaofo');
-AddTimezone('Pacific/Fiji');
-AddTimezone('Pacific/Funafuti');
-AddTimezone('Pacific/Galapagos');
-AddTimezone('Pacific/Gambier');
-AddTimezone('Pacific/Guadalcanal');
-AddTimezone('Pacific/Guam');
-AddTimezone('Pacific/Honolulu');
-AddTimezone('Pacific/Johnston');
-AddTimezone('Pacific/Kiritimati');
-AddTimezone('Pacific/Kosrae');
-AddTimezone('Pacific/Kwajalein');
-AddTimezone('Pacific/Majuro');
-AddTimezone('Pacific/Marquesas');
-AddTimezone('Pacific/Midway');
-AddTimezone('Pacific/Nauru');
-AddTimezone('Pacific/Niue');
-AddTimezone('Pacific/Norfolk');
-AddTimezone('Pacific/Noumea');
-AddTimezone('Pacific/Pago_Pago');
-AddTimezone('Pacific/Palau');
-AddTimezone('Pacific/Pitcairn');
-AddTimezone('Pacific/Ponape');
-AddTimezone('Pacific/Port_Moresby');
-AddTimezone('Pacific/Rarotonga');
-AddTimezone('Pacific/Saipan');
-AddTimezone('Pacific/Tahiti');
-AddTimezone('Pacific/Tarawa');
-AddTimezone('Pacific/Tongatapu');
-AddTimezone('Pacific/Truk');
-AddTimezone('Pacific/Wake');
-AddTimezone('Pacific/Wallis');
-AddTimezone('UTC');
+foreach (DateTimeZone::listIdentifiers() as $tz) {
+    AddTimezone($tz);
+}
 
 function AddTimezone($timezoneName)
 {
diff --git a/tpl/register.tpl b/tpl/register.tpl
index aae2117a5..38cd3542f 100644
--- a/tpl/register.tpl
+++ b/tpl/register.tpl
@@ -225,7 +225,6 @@
 
     {include file="javascript-includes.tpl" Validator=true}
 
-    {jsfile src="js/jstz.min.js"}
     {jsfile src="ajax-helpers.js"}
     {jsfile src="autocomplete.js"}
     {jsfile src="registration.js"}
@@ -236,14 +235,10 @@
         }
 
         $(document).ready(function() {
-            $('#detectTimezone').click(function(e) {
+            $('#detectTimezone').on('click', function(e) {
                 e.preventDefault();
 
-                if (Intl.DateTimeFormat) {
-                    var timezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
-                } else {
-                    var timezone = jstz.determine_timezone().name();
-                }
+                const timezone = Intl.DateTimeFormat().resolvedOptions().timeZone || "UTC";
 
                 $('#timezoneDropDown').val(timezone);
             });