I can see an extensive list of ~600 timezones suitable for use with lubridate here
If using in a shiny app, it would be handy to let a user enter their time zome from a drop down menu, but 600 options is a lot.
Is there a best practice for displaying some subset of these timezome options to users in a shiny drop down menu, so as to be compatible with lubridate but also easy for users to navigate and find their timezone? (essentially a sensible subset of the output of OlsonNames())
Note - output of OlsonNames():
[1] "Africa/Abidjan" "Africa/Accra" "Africa/Addis_Ababa" "Africa/Algiers" "Africa/Asmara" "Africa/Asmera"
[7] "Africa/Bamako" "Africa/Bangui" "Africa/Banjul" "Africa/Bissau" "Africa/Blantyre" "Africa/Brazzaville"
[13] "Africa/Bujumbura" "Africa/Cairo" "Africa/Casablanca" "Africa/Ceuta" "Africa/Conakry" "Africa/Dakar"
[19] "Africa/Dar_es_Salaam" "Africa/Djibouti" "Africa/Douala" "Africa/El_Aaiun" "Africa/Freetown" "Africa/Gaborone"
[25] "Africa/Harare" "Africa/Johannesburg" "Africa/Juba" "Africa/Kampala" "Africa/Khartoum" "Africa/Kigali"
[31] "Africa/Kinshasa" "Africa/Lagos" "Africa/Libreville" "Africa/Lome" "Africa/Luanda" "Africa/Lubumbashi"
[37] "Africa/Lusaka" "Africa/Malabo" "Africa/Maputo" "Africa/Maseru" "Africa/Mbabane" "Africa/Mogadishu"
[43] "Africa/Monrovia" "Africa/Nairobi" "Africa/Ndjamena" "Africa/Niamey" "Africa/Nouakchott" "Africa/Ouagadougou"
[49] "Africa/Porto-Novo" "Africa/Sao_Tome" "Africa/Timbuktu" "Africa/Tripoli" "Africa/Tunis" "Africa/Windhoek"
[55] "America/Adak" "America/Anchorage" "America/Anguilla" "America/Antigua" "America/Araguaina" "America/Argentina/Buenos_Aires"
[61] "America/Argentina/Catamarca" "America/Argentina/ComodRivadavia" "America/Argentina/Cordoba" "America/Argentina/Jujuy" "America/Argentina/La_Rioja" "America/Argentina/Mendoza"
[67] "America/Argentina/Rio_Gallegos" "America/Argentina/Salta" "America/Argentina/San_Juan" "America/Argentina/San_Luis" "America/Argentina/Tucuman" "America/Argentina/Ushuaia"
[73] "America/Aruba" "America/Asuncion" "America/Atikokan" "America/Atka" "America/Bahia" "America/Bahia_Banderas"
[79] "America/Barbados" "America/Belem" "America/Belize" "America/Blanc-Sablon" "America/Boa_Vista" "America/Bogota"
[85] "America/Boise" "America/Buenos_Aires" "America/Cambridge_Bay" "America/Campo_Grande" "America/Cancun" "America/Caracas"
[91] "America/Catamarca" "America/Cayenne" "America/Cayman" "America/Chicago" "America/Chihuahua" "America/Coral_Harbour"
[97] "America/Cordoba" "America/Costa_Rica" "America/Creston" "America/Cuiaba" "America/Curacao" "America/Danmarkshavn"
[103] "America/Dawson" "America/Dawson_Creek" "America/Denver" "America/Detroit" "America/Dominica" "America/Edmonton"
[109] "America/Eirunepe" "America/El_Salvador" "America/Ensenada" "America/Fort_Nelson" "America/Fort_Wayne" "America/Fortaleza"
[115] "America/Glace_Bay" "America/Godthab" "America/Goose_Bay" "America/Grand_Turk" "America/Grenada" "America/Guadeloupe"
[121] "America/Guatemala" "America/Guayaquil" "America/Guyana" "America/Halifax" "America/Havana" "America/Hermosillo"
[127] "America/Indiana/Indianapolis" "America/Indiana/Knox" "America/Indiana/Marengo" "America/Indiana/Petersburg" "America/Indiana/Tell_City" "America/Indiana/Vevay"
[133] "America/Indiana/Vincennes" "America/Indiana/Winamac" "America/Indianapolis" "America/Inuvik" "America/Iqaluit" "America/Jamaica"
[139] "America/Jujuy" "America/Juneau" "America/Kentucky/Louisville" "America/Kentucky/Monticello" "America/Knox_IN" "America/Kralendijk"
[145] "America/La_Paz" "America/Lima" "America/Los_Angeles" "America/Louisville" "America/Lower_Princes" "America/Maceio"
[151] "America/Managua" "America/Manaus" "America/Marigot" "America/Martinique" "America/Matamoros" "America/Mazatlan"
[157] "America/Mendoza" "America/Menominee" "America/Merida" "America/Metlakatla" "America/Mexico_City" "America/Miquelon"
[163] "America/Moncton" "America/Monterrey" "America/Montevideo" "America/Montreal" "America/Montserrat" "America/Nassau"
[169] "America/New_York" "America/Nipigon" "America/Nome" "America/Noronha" "America/North_Dakota/Beulah" "America/North_Dakota/Center"
[175] "America/North_Dakota/New_Salem" "America/Nuuk" "America/Ojinaga" "America/Panama" "America/Pangnirtung" "America/Paramaribo"
[181] "America/Phoenix" "America/Port_of_Spain" "America/Port-au-Prince" "America/Porto_Acre" "America/Porto_Velho" "America/Puerto_Rico"
[187] "America/Punta_Arenas" "America/Rainy_River" "America/Rankin_Inlet" "America/Recife" "America/Regina" "America/Resolute"
[193] "America/Rio_Branco" "America/Rosario" "America/Santa_Isabel" "America/Santarem" "America/Santiago" "America/Santo_Domingo"
[199] "America/Sao_Paulo" "America/Scoresbysund" "America/Shiprock" "America/Sitka" "America/St_Barthelemy" "America/St_Johns"
[205] "America/St_Kitts" "America/St_Lucia" "America/St_Thomas" "America/St_Vincent" "America/Swift_Current" "America/Tegucigalpa"
[211] "America/Thule" "America/Thunder_Bay" "America/Tijuana" "America/Toronto" "America/Tortola" "America/Vancouver"
[217] "America/Virgin" "America/Whitehorse" "America/Winnipeg" "America/Yakutat" "America/Yellowknife" "Antarctica/Casey"
[223] "Antarctica/Davis" "Antarctica/DumontDUrville" "Antarctica/Macquarie" "Antarctica/Mawson" "Antarctica/McMurdo" "Antarctica/Palmer"
[229] "Antarctica/Rothera" "Antarctica/South_Pole" "Antarctica/Syowa" "Antarctica/Troll" "Antarctica/Vostok" "Arctic/Longyearbyen"
[235] "Asia/Aden" "Asia/Almaty" "Asia/Amman" "Asia/Anadyr" "Asia/Aqtau" "Asia/Aqtobe"
[241] "Asia/Ashgabat" "Asia/Ashkhabad" "Asia/Atyrau" "Asia/Baghdad" "Asia/Bahrain" "Asia/Baku"
[247] "Asia/Bangkok" "Asia/Barnaul" "Asia/Beirut" "Asia/Bishkek" "Asia/Brunei" "Asia/Calcutta"
[253] "Asia/Chita" "Asia/Choibalsan" "Asia/Chongqing" "Asia/Chungking" "Asia/Colombo" "Asia/Dacca"
[259] "Asia/Damascus" "Asia/Dhaka" "Asia/Dili" "Asia/Dubai" "Asia/Dushanbe" "Asia/Famagusta"
[265] "Asia/Gaza" "Asia/Harbin" "Asia/Hebron" "Asia/Ho_Chi_Minh" "Asia/Hong_Kong" "Asia/Hovd"
[271] "Asia/Irkutsk" "Asia/Istanbul" "Asia/Jakarta" "Asia/Jayapura" "Asia/Jerusalem" "Asia/Kabul"
[277] "Asia/Kamchatka" "Asia/Karachi" "Asia/Kashgar" "Asia/Kathmandu" "Asia/Katmandu" "Asia/Khandyga"
[283] "Asia/Kolkata" "Asia/Krasnoyarsk" "Asia/Kuala_Lumpur" "Asia/Kuching" "Asia/Kuwait" "Asia/Macao"
[289] "Asia/Macau" "Asia/Magadan" "Asia/Makassar" "Asia/Manila" "Asia/Muscat" "Asia/Nicosia"
[295] "Asia/Novokuznetsk" "Asia/Novosibirsk" "Asia/Omsk" "Asia/Oral" "Asia/Phnom_Penh" "Asia/Pontianak"
[301] "Asia/Pyongyang" "Asia/Qatar" "Asia/Qostanay" "Asia/Qyzylorda" "Asia/Rangoon" "Asia/Riyadh"
[307] "Asia/Saigon" "Asia/Sakhalin" "Asia/Samarkand" "Asia/Seoul" "Asia/Shanghai" "Asia/Singapore"
[313] "Asia/Srednekolymsk" "Asia/Taipei" "Asia/Tashkent" "Asia/Tbilisi" "Asia/Tehran" "Asia/Tel_Aviv"
[319] "Asia/Thimbu" "Asia/Thimphu" "Asia/Tokyo" "Asia/Tomsk" "Asia/Ujung_Pandang" "Asia/Ulaanbaatar"
[325] "Asia/Ulan_Bator" "Asia/Urumqi" "Asia/Ust-Nera" "Asia/Vientiane" "Asia/Vladivostok" "Asia/Yakutsk"
[331] "Asia/Yangon" "Asia/Yekaterinburg" "Asia/Yerevan" "Atlantic/Azores" "Atlantic/Bermuda" "Atlantic/Canary"
[337] "Atlantic/Cape_Verde" "Atlantic/Faeroe" "Atlantic/Faroe" "Atlantic/Jan_Mayen" "Atlantic/Madeira" "Atlantic/Reykjavik"
[343] "Atlantic/South_Georgia" "Atlantic/St_Helena" "Atlantic/Stanley" "Australia/ACT" "Australia/Adelaide" "Australia/Brisbane"
[349] "Australia/Broken_Hill" "Australia/Canberra" "Australia/Currie" "Australia/Darwin" "Australia/Eucla" "Australia/Hobart"
[355] "Australia/LHI" "Australia/Lindeman" "Australia/Lord_Howe" "Australia/Melbourne" "Australia/North" "Australia/NSW"
[361] "Australia/Perth" "Australia/Queensland" "Australia/South" "Australia/Sydney" "Australia/Tasmania" "Australia/Victoria"
[367] "Australia/West" "Australia/Yancowinna" "Brazil/Acre" "Brazil/DeNoronha" "Brazil/East" "Brazil/West"
[373] "Canada/Atlantic" "Canada/Central" "Canada/Eastern" "Canada/Mountain" "Canada/Newfoundland" "Canada/Pacific"
[379] "Canada/Saskatchewan" "Canada/Yukon" "CET" "Chile/Continental" "Chile/EasterIsland" "CST6CDT"
[385] "Cuba" "EET" "Egypt" "Eire" "EST" "EST5EDT"
[391] "Etc/GMT" "Etc/GMT-0" "Etc/GMT-1" "Etc/GMT-10" "Etc/GMT-11" "Etc/GMT-12"
[397] "Etc/GMT-13" "Etc/GMT-14" "Etc/GMT-2" "Etc/GMT-3" "Etc/GMT-4" "Etc/GMT-5"
[403] "Etc/GMT-6" "Etc/GMT-7" "Etc/GMT-8" "Etc/GMT-9" "Etc/GMT+0" "Etc/GMT+1"
[409] "Etc/GMT+10" "Etc/GMT+11" "Etc/GMT+12" "Etc/GMT+2" "Etc/GMT+3" "Etc/GMT+4"
[415] "Etc/GMT+5" "Etc/GMT+6" "Etc/GMT+7" "Etc/GMT+8" "Etc/GMT+9" "Etc/GMT0"
[421] "Etc/Greenwich" "Etc/UCT" "Etc/Universal" "Etc/UTC" "Etc/Zulu" "Europe/Amsterdam"
[427] "Europe/Andorra" "Europe/Astrakhan" "Europe/Athens" "Europe/Belfast" "Europe/Belgrade" "Europe/Berlin"
[433] "Europe/Bratislava" "Europe/Brussels" "Europe/Bucharest" "Europe/Budapest" "Europe/Busingen" "Europe/Chisinau"
[439] "Europe/Copenhagen" "Europe/Dublin" "Europe/Gibraltar" "Europe/Guernsey" "Europe/Helsinki" "Europe/Isle_of_Man"
[445] "Europe/Istanbul" "Europe/Jersey" "Europe/Kaliningrad" "Europe/Kiev" "Europe/Kirov" "Europe/Lisbon"
[451] "Europe/Ljubljana" "Europe/London" "Europe/Luxembourg" "Europe/Madrid" "Europe/Malta" "Europe/Mariehamn"
[457] "Europe/Minsk" "Europe/Monaco" "Europe/Moscow" "Europe/Nicosia" "Europe/Oslo" "Europe/Paris"
[463] "Europe/Podgorica" "Europe/Prague" "Europe/Riga" "Europe/Rome" "Europe/Samara" "Europe/San_Marino"
[469] "Europe/Sarajevo" "Europe/Saratov" "Europe/Simferopol" "Europe/Skopje" "Europe/Sofia" "Europe/Stockholm"
[475] "Europe/Tallinn" "Europe/Tirane" "Europe/Tiraspol" "Europe/Ulyanovsk" "Europe/Uzhgorod" "Europe/Vaduz"
[481] "Europe/Vatican" "Europe/Vienna" "Europe/Vilnius" "Europe/Volgograd" "Europe/Warsaw" "Europe/Zagreb"
[487] "Europe/Zaporozhye" "Europe/Zurich" "GB" "GB-Eire" "GMT" "GMT-0"
[493] "GMT+0" "GMT0" "Greenwich" "Hongkong" "HST" "Iceland"
[499] "Indian/Antananarivo" "Indian/Chagos" "Indian/Christmas" "Indian/Cocos" "Indian/Comoro" "Indian/Kerguelen"
[505] "Indian/Mahe" "Indian/Maldives" "Indian/Mauritius" "Indian/Mayotte" "Indian/Reunion" "Iran"
[511] "Israel" "Jamaica" "Japan" "Kwajalein" "Libya" "MET"
[517] "Mexico/BajaNorte" "Mexico/BajaSur" "Mexico/General" "MST" "MST7MDT" "Navajo"
[523] "NZ" "NZ-CHAT" "Pacific/Apia" "Pacific/Auckland" "Pacific/Bougainville" "Pacific/Chatham"
[529] "Pacific/Chuuk" "Pacific/Easter" "Pacific/Efate" "Pacific/Enderbury" "Pacific/Fakaofo" "Pacific/Fiji"
[535] "Pacific/Funafuti" "Pacific/Galapagos" "Pacific/Gambier" "Pacific/Guadalcanal" "Pacific/Guam" "Pacific/Honolulu"
[541] "Pacific/Johnston" "Pacific/Kiritimati" "Pacific/Kosrae" "Pacific/Kwajalein" "Pacific/Majuro" "Pacific/Marquesas"
[547] "Pacific/Midway" "Pacific/Nauru" "Pacific/Niue" "Pacific/Norfolk" "Pacific/Noumea" "Pacific/Pago_Pago"
[553] "Pacific/Palau" "Pacific/Pitcairn" "Pacific/Pohnpei" "Pacific/Ponape" "Pacific/Port_Moresby" "Pacific/Rarotonga"
[559] "Pacific/Saipan" "Pacific/Samoa" "Pacific/Tahiti" "Pacific/Tarawa" "Pacific/Tongatapu" "Pacific/Truk"
[565] "Pacific/Wake" "Pacific/Wallis" "Pacific/Yap" "Poland" "Portugal" "PRC"
[571] "PST8PDT" "ROC" "ROK" "Singapore" "Turkey" "UCT"
[577] "Universal" "US/Alaska" "US/Aleutian" "US/Arizona" "US/Central" "US/East-Indiana"
[583] "US/Eastern" "US/Hawaii" "US/Indiana-Starke" "US/Michigan" "US/Mountain" "US/Pacific"
[589] "US/Pacific-New" "US/Samoa" "UTC" "W-SU" "WET" "Zulu"
