RAM efficient version of `fourTwentyTz.js`

As suggested by @gfwilliams here:
https://github.com/espruino/BangleApps/pull/1152#issuecomment-1009739110

Also make `apps.json` entry more accurate, and play nice with dark theme.

apps.json

@@ -5169,14 +5169,13 @@
   {
     "id": "ftclock",
     "name": "Four Twenty Clock",
-    "version": "0.01",
+    "version": "0.02",
     "description": "A clock that tells when and where it's going to be 4:20 next",
     "icon": "app.png",
     "screenshots": [{"url":"screenshot.png"}, {"url":"screenshot1.png"}],
     "type": "clock",
     "tags": "clock",
-    "supports": ["BANGLEJS","BANGLEJS2"],
+    "supports": ["BANGLEJS2"],
-    "allow_emulator": true,
     "readme": "README.md",
     "storage": [
       {"name":"ftclock.app.js","url":"app.js"},

apps/ftclock/ChangeLog

@@ -1 +1,2 @@
 0.01: first release
+0.02: RAM efficient version of `fourTwentyTz.js` (as suggested by @gfwilliams).

apps/ftclock/app.js

@@ -17,14 +17,13 @@ function queueDraw() {
 
 function draw() {
   g.reset();
-  g.setBgColor("#ffffff");
   let date = new Date();
   let timeStr = require("locale").time(date,1);
   let next420 = getNextFourTwenty();
   g.clearRect(0,26,g.getWidth(),g.getHeight());
   g.setColor("#00ff00").setFontAlign(0,-1).setFont("Teletext10x18Ascii",2);
   g.drawString(next420.minutes? timeStr: `\0${leaf_img}${timeStr}\0${leaf_img}`, g.getWidth()/2, 28);
-  g.setColor("#000000");
+  g.setColor(g.theme.fg);
   g.setFontAlign(-1,-1).setFont("Teletext10x18Ascii");
   g.drawString(g.wrapString(next420.text, g.getWidth()-8).join("\n"),4,60);
 

apps/ftclock/fourTwenty.js

@@ -1,4 +1,6 @@
-let timezones = require("fourTwentyTz").timezones;
+let ftz = require("fourTwentyTz"),
+    offsets = ftz.offsets,
+    timezones = ftz.timezones;
 
 function get420offset() {
   let current_time = Math.floor((Date.now()%(24*3600*1000))/60000);
@@ -24,10 +26,10 @@ function makeFourTwentyText(minutes, places) {
 
 function getNextFourTwenty() {
   let offs = get420offset();
-  for (let i=0; i<timezones.length; i++) {
+  for (let i=0; i<offsets.length; i++) {
-    if (timezones[i][0]<=offs) {
+    if (offsets[i]<=offs) {
-      let minutes = offs-timezones[i][0];
+      let minutes = offs-offsets[i];
-      let places = timezones[i][1];
+      let places = timezones(offsets[i]);
       return {
         minutes: minutes,
         places: places,

apps/ftclock/fourTwentyTz.js

@@ -1,463 +1,33 @@
 // Generated by mkFourTwentyTz.js
+// Wed Jan 12 2022 17:49:39 GMT+0200 (Israel Standard Time)
 // Data source: https://timezonedb.com/files/timezonedb.csv.zip
-// Sun Jan 09 2022 13:21:47 GMT+0200 (Israel Standard Time)
+exports.offsets = [1380,1320,1260,1200,1140,1080,1020,960,900,840,780,720,660,600,540,480,420,360,300,240,180,120,60,0];
-exports.timezones = {
+exports.timezones = function(offs) {
-    "0": [
+  switch (offs) {
-        "Troll, Antarctica",
+    case 0: return ["Troll, Antarctica","Ouagadougou, Burkina Faso","Abidjan, Côte d'Ivoire","Canary, Spain","Faroe, Faroe Islands","London, United Kingdom of Great Britain and Northern Ireland","Guernsey, Guernsey","Accra, Ghana","Danmarkshavn, Greenland","Banjul, Gambia","Conakry, Guinea","Bissau, Guinea-Bissau","Dublin, Ireland","Isle of_Man, Isle of Man","Reykjavik, Iceland","Jersey, Jersey","Monrovia, Liberia","Bamako, Mali","Nouakchott, Mauritania","Lisbon, Portugal","Madeira, Portugal","St Helena, Saint Helena, Ascension and Tristan da Cunha","Freetown, Sierra Leone","Dakar, Senegal","Sao Tome, Sao Tome and Principe","Lome, Togo"];
-        "Ouagadougou, Burkina Faso",
+    case 60: return ["Andorra, Andorra","Tirane, Albania","Luanda, Angola","Vienna, Austria","Sarajevo, Bosnia and Herzegovina","Brussels, Belgium","Porto-Novo, Benin","Kinshasa, Congo, Democratic Republic of the","Bangui, Central African Republic","Brazzaville, Congo","Zurich, Switzerland","Douala, Cameroon","Prague, Czechia","Berlin, Germany","Busingen, Germany","Copenhagen, Denmark","Algiers, Algeria","El Aaiun, Western Sahara","Madrid, Spain","Ceuta, Spain","Paris, France","Libreville, Gabon","Gibraltar, Gibraltar","Malabo, Equatorial Guinea","Zagreb, Croatia","Budapest, Hungary","Rome, Italy","Vaduz, Liechtenstein","Luxembourg, Luxembourg","Casablanca, Morocco","Monaco, Monaco","Podgorica, Montenegro","Skopje, North Macedonia","Malta, Malta","Niamey, Niger","Lagos, Nigeria","Amsterdam, Netherlands","Oslo, Norway","Warsaw, Poland","Belgrade, Serbia","Stockholm, Sweden","Ljubljana, Slovenia","Longyearbyen, Svalbard and Jan Mayen","Bratislava, Slovakia","San Marino, San Marino","Ndjamena, Chad","Tunis, Tunisia","Vatican, Holy See"];
-        "Abidjan, Côte d'Ivoire",
+    case 120: return ["Mariehamn, Åland Islands","Sofia, Bulgaria","Bujumbura, Burundi","Gaborone, Botswana","Lubumbashi, Congo, Democratic Republic of the","Nicosia, Cyprus","Famagusta, Cyprus","Tallinn, Estonia","Cairo, Egypt","Helsinki, Finland","Athens, Greece","Jerusalem, Israel","Amman, Jordan","Beirut, Lebanon","Maseru, Lesotho","Vilnius, Lithuania","Riga, Latvia","Tripoli, Libya","Chisinau, Moldova, Republic of","Blantyre, Malawi","Maputo, Mozambique","Windhoek, Namibia","Gaza, Palestine, State of","Hebron, Palestine, State of","Bucharest, Romania","Kaliningrad, Russian Federation","Kigali, Rwanda","Khartoum, Sudan","Juba, South Sudan","Damascus, Syrian Arab Republic","Mbabane, Eswatini","Kiev, Ukraine","Uzhgorod, Ukraine","Zaporozhye, Ukraine","Johannesburg, South Africa","Lusaka, Zambia","Harare, Zimbabwe"];
-        "Canary, Spain",
+    case 180: return ["Syowa, Antarctica","Bahrain, Bahrain","Minsk, Belarus","Djibouti, Djibouti","Asmara, Eritrea","Addis Ababa, Ethiopia","Baghdad, Iraq","Nairobi, Kenya","Comoro, Comoros","Kuwait, Kuwait","Antananarivo, Madagascar","Qatar, Qatar","Moscow, Russian Federation","Simferopol, Ukraine","Kirov, Russian Federation","Volgograd, Russian Federation","Riyadh, Saudi Arabia","Mogadishu, Somalia","Istanbul, Turkey","Dar es_Salaam, Tanzania, United Republic of","Kampala, Uganda","Aden, Yemen","Mayotte, Mayotte"];
-        "Faroe, Faroe Islands",
+    case 240: return ["Dubai, United Arab Emirates","Yerevan, Armenia","Baku, Azerbaijan","Tbilisi, Georgia","Mauritius, Mauritius","Muscat, Oman","Reunion, Réunion","Astrakhan, Russian Federation","Saratov, Russian Federation","Ulyanovsk, Russian Federation","Samara, Russian Federation","Mahe, Seychelles"];
-        "London, United Kingdom of Great Britain and Northern Ireland",
+    case 360: return ["Vostok, Antarctica","Dhaka, Bangladesh","Thimphu, Bhutan","Urumqi, China","Chagos, British Indian Ocean Territory","Bishkek, Kyrgyzstan","Almaty, Kazakhstan","Qostanay, Kazakhstan","Omsk, Russian Federation"];
-        "Guernsey, Guernsey",
+    case 300: return ["Mawson, Antarctica","Qyzylorda, Kazakhstan","Aqtobe, Kazakhstan","Aqtau, Kazakhstan","Atyrau, Kazakhstan","Oral, Kazakhstan","Maldives, Maldives","Karachi, Pakistan","Yekaterinburg, Russian Federation","Kerguelen, French Southern Territories","Dushanbe, Tajikistan","Ashgabat, Turkmenistan","Samarkand, Uzbekistan","Tashkent, Uzbekistan"];
-        "Accra, Ghana",
+    case 420: return ["Davis, Antarctica","Christmas, Christmas Island","Jakarta, Indonesia","Pontianak, Indonesia","Phnom Penh, Cambodia","Vientiane, Lao People's Democratic Republic","Hovd, Mongolia","Novosibirsk, Russian Federation","Barnaul, Russian Federation","Tomsk, Russian Federation","Novokuznetsk, Russian Federation","Krasnoyarsk, Russian Federation","Bangkok, Thailand","Ho Chi_Minh, Viet Nam"];
-        "Danmarkshavn, Greenland",
+    case 480: return ["Perth, Australia","Brunei, Brunei Darussalam","Shanghai, China","Hong Kong, Hong Kong","Makassar, Indonesia","Ulaanbaatar, Mongolia","Choibalsan, Mongolia","Macau, Macao","Kuala Lumpur, Malaysia","Kuching, Malaysia","Manila, Philippines","Irkutsk, Russian Federation","Singapore, Singapore","Taipei, Taiwan, Province of China"];
-        "Banjul, Gambia",
+    case 540: return ["Jayapura, Indonesia","Tokyo, Japan","Pyongyang, Korea (Democratic People's Republic of)","Seoul, Korea, Republic of","Palau, Palau","Chita, Russian Federation","Yakutsk, Russian Federation","Khandyga, Russian Federation","Dili, Timor-Leste"];
-        "Conakry, Guinea",
+    case 600: return ["DumontDUrville, Antarctica","Brisbane, Australia","Lindeman, Australia","Chuuk, Micronesia (Federated States of)","Guam, Guam","Saipan, Northern Mariana Islands","Port Moresby, Papua New Guinea","Vladivostok, Russian Federation","Ust-Nera, Russian Federation"];
-        "Bissau, Guinea-Bissau",
+    case 660: return ["Casey, Antarctica","Lord Howe, Australia","Macquarie, Australia","Hobart, Australia","Melbourne, Australia","Sydney, Australia","Pohnpei, Micronesia (Federated States of)","Kosrae, Micronesia (Federated States of)","Noumea, New Caledonia","Bougainville, Papua New Guinea","Magadan, Russian Federation","Sakhalin, Russian Federation","Srednekolymsk, Russian Federation","Guadalcanal, Solomon Islands","Efate, Vanuatu"];
-        "Dublin, Ireland",
+    case 720: return ["Tarawa, Kiribati","Majuro, Marshall Islands","Kwajalein, Marshall Islands","Norfolk, Norfolk Island","Nauru, Nauru","Kamchatka, Russian Federation","Anadyr, Russian Federation","Funafuti, Tuvalu","Wake, United States Minor Outlying Islands","Wallis, Wallis and Futuna"];
-        "Isle of_Man, Isle of Man",
+    case 780: return ["McMurdo, Antarctica","Pago Pago, American Samoa","Fiji, Fiji","Kanton, Kiribati","Niue, Niue","Auckland, New Zealand","Fakaofo, Tokelau","Tongatapu, Tonga","Midway, United States Minor Outlying Islands","Apia, Samoa"];
-        "Reykjavik, Iceland",
+    case 840: return ["Rarotonga, Cook Islands","Kiritimati, Kiribati","Tahiti, French Polynesia","Adak, United States of America","Honolulu, United States of America"];
-        "Jersey, Jersey",
+    case 900: return ["Gambier, French Polynesia","Anchorage, United States of America","Juneau, United States of America","Sitka, United States of America","Metlakatla, United States of America","Yakutat, United States of America","Nome, United States of America"];
-        "Monrovia, Liberia",
+    case 960: return ["Vancouver, Canada","Tijuana, Mexico","Pitcairn, Pitcairn","Los Angeles, United States of America"];
-        "Bamako, Mali",
+    case 1020: return ["Edmonton, Canada","Cambridge Bay, Canada","Yellowknife, Canada","Inuvik, Canada","Creston, Canada","Dawson Creek, Canada","Fort Nelson, Canada","Whitehorse, Canada","Dawson, Canada","Mazatlan, Mexico","Chihuahua, Mexico","Ojinaga, Mexico","Hermosillo, Mexico","Denver, United States of America","Boise, United States of America","Phoenix, United States of America"];
-        "Nouakchott, Mauritania",
+    case 1080: return ["Belize, Belize","Winnipeg, Canada","Rainy River, Canada","Resolute, Canada","Rankin Inlet, Canada","Regina, Canada","Swift Current, Canada","Costa Rica, Costa Rica","Galapagos, Ecuador","Guatemala, Guatemala","Tegucigalpa, Honduras","Mexico City, Mexico","Merida, Mexico","Monterrey, Mexico","Matamoros, Mexico","Bahia Banderas, Mexico","Managua, Nicaragua","El Salvador, El Salvador","Chicago, United States of America","Tell City, Indiana","Knox, Indiana","Menominee, United States of America","Center, North Dakota","New_Salem, North Dakota","Beulah, North Dakota"];
-        "Lisbon, Portugal",
+    case 1140: return ["Eirunepe, Brazil","Rio Branco, Brazil","Nassau, Bahamas","Toronto, Canada","Nipigon, Canada","Thunder Bay, Canada","Iqaluit, Canada","Pangnirtung, Canada","Atikokan, Canada","Easter, Chile","Bogota, Colombia","Havana, Cuba","Guayaquil, Ecuador","Port-au-Prince, Haiti","Jamaica, Jamaica","Cayman, Cayman Islands","Cancun, Mexico","Panama, Panama","Lima, Peru","Grand Turk, Turks and Caicos Islands","New York, United States of America","Detroit, United States of America","Louisville, Kentucky","Monticello, Kentucky","Indianapolis, Indiana","Vincennes, Indiana","Winamac, Indiana","Marengo, Indiana","Petersburg, Indiana","Vevay, Indiana"];
-        "Madeira, Portugal",
+    case 1200: return ["Antigua, Antigua and Barbuda","Anguilla, Anguilla","Aruba, Aruba","Barbados, Barbados","St Barthelemy, Saint Barthélemy","Bermuda, Bermuda","La Paz, Bolivia (Plurinational State of)","Kralendijk, Bonaire, Sint Eustatius and Saba","Campo Grande, Brazil","Cuiaba, Brazil","Porto Velho, Brazil","Boa Vista, Brazil","Manaus, Brazil","Halifax, Canada","Glace Bay, Canada","Moncton, Canada","Goose Bay, Canada","Blanc-Sablon, Canada","Curacao, Curaçao","Dominica, Dominica","Santo Domingo, Dominican Republic","Grenada, Grenada","Thule, Greenland","Guadeloupe, Guadeloupe","Guyana, Guyana","St Kitts, Saint Kitts and Nevis","St Lucia, Saint Lucia","Marigot, Saint Martin (French part)","Martinique, Martinique","Montserrat, Montserrat","Puerto Rico, Puerto Rico","Lower Princes, Sint Maarten (Dutch part)","Port of_Spain, Trinidad and Tobago","St Vincent, Saint Vincent and the Grenadines","Caracas, Venezuela (Bolivarian Republic of)","Tortola, Virgin Islands (British)","St Thomas, Virgin Islands (U.S.)"];
-        "St Helena, Saint Helena, Ascension and Tristan da Cunha",
+    case 1260: return ["Palmer, Antarctica","Rothera, Antarctica","Buenos Aires, Argentina","Cordoba, Argentina","Salta, Argentina","Jujuy, Argentina","Tucuman, Argentina","Catamarca, Argentina","La Rioja, Argentina","San Juan, Argentina","Mendoza, Argentina","San Luis, Argentina","Rio Gallegos, Argentina","Ushuaia, Argentina","Belem, Brazil","Fortaleza, Brazil","Recife, Brazil","Araguaina, Brazil","Maceio, Brazil","Bahia, Brazil","Sao Paulo, Brazil","Santarem, Brazil","Santiago, Chile","Punta Arenas, Chile","Stanley, Falkland Islands (Malvinas)","Cayenne, French Guiana","Nuuk, Greenland","Miquelon, Saint Pierre and Miquelon","Asuncion, Paraguay","Paramaribo, Suriname","Montevideo, Uruguay"];
-        "Freetown, Sierra Leone",
+    case 1320: return ["Noronha, Brazil","South Georgia, South Georgia and the South Sandwich Islands"];
-        "Dakar, Senegal",
+    case 1380: return ["Cape Verde, Cabo Verde","Scoresbysund, Greenland","Azores, Portugal"];
-        "Sao Tome, Sao Tome and Principe",
+    default: return ["Houston, we have a bug."];
-        "Lome, Togo"
+  };
-    ],
+};
-    "60": [
-        "Andorra, Andorra",
-        "Tirane, Albania",
-        "Luanda, Angola",
-        "Vienna, Austria",
-        "Sarajevo, Bosnia and Herzegovina",
-        "Brussels, Belgium",
-        "Porto-Novo, Benin",
-        "Kinshasa, Congo, Democratic Republic of the",
-        "Bangui, Central African Republic",
-        "Brazzaville, Congo",
-        "Zurich, Switzerland",
-        "Douala, Cameroon",
-        "Prague, Czechia",
-        "Berlin, Germany",
-        "Busingen, Germany",
-        "Copenhagen, Denmark",
-        "Algiers, Algeria",
-        "El Aaiun, Western Sahara",
-        "Madrid, Spain",
-        "Ceuta, Spain",
-        "Paris, France",
-        "Libreville, Gabon",
-        "Gibraltar, Gibraltar",
-        "Malabo, Equatorial Guinea",
-        "Zagreb, Croatia",
-        "Budapest, Hungary",
-        "Rome, Italy",
-        "Vaduz, Liechtenstein",
-        "Luxembourg, Luxembourg",
-        "Casablanca, Morocco",
-        "Monaco, Monaco",
-        "Podgorica, Montenegro",
-        "Skopje, North Macedonia",
-        "Malta, Malta",
-        "Niamey, Niger",
-        "Lagos, Nigeria",
-        "Amsterdam, Netherlands",
-        "Oslo, Norway",
-        "Warsaw, Poland",
-        "Belgrade, Serbia",
-        "Stockholm, Sweden",
-        "Ljubljana, Slovenia",
-        "Longyearbyen, Svalbard and Jan Mayen",
-        "Bratislava, Slovakia",
-        "San Marino, San Marino",
-        "Ndjamena, Chad",
-        "Tunis, Tunisia",
-        "Vatican, Holy See"
-    ],
-    "120": [
-        "Mariehamn, Åland Islands",
-        "Sofia, Bulgaria",
-        "Bujumbura, Burundi",
-        "Gaborone, Botswana",
-        "Lubumbashi, Congo, Democratic Republic of the",
-        "Nicosia, Cyprus",
-        "Famagusta, Cyprus",
-        "Tallinn, Estonia",
-        "Cairo, Egypt",
-        "Helsinki, Finland",
-        "Athens, Greece",
-        "Jerusalem, Israel",
-        "Amman, Jordan",
-        "Beirut, Lebanon",
-        "Maseru, Lesotho",
-        "Vilnius, Lithuania",
-        "Riga, Latvia",
-        "Tripoli, Libya",
-        "Chisinau, Moldova, Republic of",
-        "Blantyre, Malawi",
-        "Maputo, Mozambique",
-        "Windhoek, Namibia",
-        "Gaza, Palestine, State of",
-        "Hebron, Palestine, State of",
-        "Bucharest, Romania",
-        "Kaliningrad, Russian Federation",
-        "Kigali, Rwanda",
-        "Khartoum, Sudan",
-        "Juba, South Sudan",
-        "Damascus, Syrian Arab Republic",
-        "Mbabane, Eswatini",
-        "Kiev, Ukraine",
-        "Uzhgorod, Ukraine",
-        "Zaporozhye, Ukraine",
-        "Johannesburg, South Africa",
-        "Lusaka, Zambia",
-        "Harare, Zimbabwe"
-    ],
-    "180": [
-        "Syowa, Antarctica",
-        "Bahrain, Bahrain",
-        "Minsk, Belarus",
-        "Djibouti, Djibouti",
-        "Asmara, Eritrea",
-        "Addis Ababa, Ethiopia",
-        "Baghdad, Iraq",
-        "Nairobi, Kenya",
-        "Comoro, Comoros",
-        "Kuwait, Kuwait",
-        "Antananarivo, Madagascar",
-        "Qatar, Qatar",
-        "Moscow, Russian Federation",
-        "Simferopol, Ukraine",
-        "Kirov, Russian Federation",
-        "Volgograd, Russian Federation",
-        "Riyadh, Saudi Arabia",
-        "Mogadishu, Somalia",
-        "Istanbul, Turkey",
-        "Dar es_Salaam, Tanzania, United Republic of",
-        "Kampala, Uganda",
-        "Aden, Yemen",
-        "Mayotte, Mayotte"
-    ],
-    "240": [
-        "Dubai, United Arab Emirates",
-        "Yerevan, Armenia",
-        "Baku, Azerbaijan",
-        "Tbilisi, Georgia",
-        "Mauritius, Mauritius",
-        "Muscat, Oman",
-        "Reunion, Réunion",
-        "Astrakhan, Russian Federation",
-        "Saratov, Russian Federation",
-        "Ulyanovsk, Russian Federation",
-        "Samara, Russian Federation",
-        "Mahe, Seychelles"
-    ],
-    "300": [
-        "Mawson, Antarctica",
-        "Qyzylorda, Kazakhstan",
-        "Aqtobe, Kazakhstan",
-        "Aqtau, Kazakhstan",
-        "Atyrau, Kazakhstan",
-        "Oral, Kazakhstan",
-        "Maldives, Maldives",
-        "Karachi, Pakistan",
-        "Yekaterinburg, Russian Federation",
-        "Kerguelen, French Southern Territories",
-        "Dushanbe, Tajikistan",
-        "Ashgabat, Turkmenistan",
-        "Samarkand, Uzbekistan",
-        "Tashkent, Uzbekistan"
-    ],
-    "360": [
-        "Vostok, Antarctica",
-        "Dhaka, Bangladesh",
-        "Thimphu, Bhutan",
-        "Urumqi, China",
-        "Chagos, British Indian Ocean Territory",
-        "Bishkek, Kyrgyzstan",
-        "Almaty, Kazakhstan",
-        "Qostanay, Kazakhstan",
-        "Omsk, Russian Federation"
-    ],
-    "420": [
-        "Davis, Antarctica",
-        "Christmas, Christmas Island",
-        "Jakarta, Indonesia",
-        "Pontianak, Indonesia",
-        "Phnom Penh, Cambodia",
-        "Vientiane, Lao People's Democratic Republic",
-        "Hovd, Mongolia",
-        "Novosibirsk, Russian Federation",
-        "Barnaul, Russian Federation",
-        "Tomsk, Russian Federation",
-        "Novokuznetsk, Russian Federation",
-        "Krasnoyarsk, Russian Federation",
-        "Bangkok, Thailand",
-        "Ho Chi_Minh, Viet Nam"
-    ],
-    "480": [
-        "Perth, Australia",
-        "Brunei, Brunei Darussalam",
-        "Shanghai, China",
-        "Hong Kong, Hong Kong",
-        "Makassar, Indonesia",
-        "Ulaanbaatar, Mongolia",
-        "Choibalsan, Mongolia",
-        "Macau, Macao",
-        "Kuala Lumpur, Malaysia",
-        "Kuching, Malaysia",
-        "Manila, Philippines",
-        "Irkutsk, Russian Federation",
-        "Singapore, Singapore",
-        "Taipei, Taiwan, Province of China"
-    ],
-    "540": [
-        "Jayapura, Indonesia",
-        "Tokyo, Japan",
-        "Pyongyang, Korea (Democratic People's Republic of)",
-        "Seoul, Korea, Republic of",
-        "Palau, Palau",
-        "Chita, Russian Federation",
-        "Yakutsk, Russian Federation",
-        "Khandyga, Russian Federation",
-        "Dili, Timor-Leste"
-    ],
-    "600": [
-        "DumontDUrville, Antarctica",
-        "Brisbane, Australia",
-        "Lindeman, Australia",
-        "Chuuk, Micronesia (Federated States of)",
-        "Guam, Guam",
-        "Saipan, Northern Mariana Islands",
-        "Port Moresby, Papua New Guinea",
-        "Vladivostok, Russian Federation",
-        "Ust-Nera, Russian Federation"
-    ],
-    "660": [
-        "Casey, Antarctica",
-        "Lord Howe, Australia",
-        "Macquarie, Australia",
-        "Hobart, Australia",
-        "Melbourne, Australia",
-        "Sydney, Australia",
-        "Pohnpei, Micronesia (Federated States of)",
-        "Kosrae, Micronesia (Federated States of)",
-        "Noumea, New Caledonia",
-        "Bougainville, Papua New Guinea",
-        "Magadan, Russian Federation",
-        "Sakhalin, Russian Federation",
-        "Srednekolymsk, Russian Federation",
-        "Guadalcanal, Solomon Islands",
-        "Efate, Vanuatu"
-    ],
-    "720": [
-        "Tarawa, Kiribati",
-        "Majuro, Marshall Islands",
-        "Kwajalein, Marshall Islands",
-        "Norfolk, Norfolk Island",
-        "Nauru, Nauru",
-        "Kamchatka, Russian Federation",
-        "Anadyr, Russian Federation",
-        "Funafuti, Tuvalu",
-        "Wake, United States Minor Outlying Islands",
-        "Wallis, Wallis and Futuna"
-    ],
-    "780": [
-        "McMurdo, Antarctica",
-        "Pago Pago, American Samoa",
-        "Fiji, Fiji",
-        "Kanton, Kiribati",
-        "Niue, Niue",
-        "Auckland, New Zealand",
-        "Fakaofo, Tokelau",
-        "Tongatapu, Tonga",
-        "Midway, United States Minor Outlying Islands",
-        "Apia, Samoa"
-    ],
-    "840": [
-        "Rarotonga, Cook Islands",
-        "Kiritimati, Kiribati",
-        "Tahiti, French Polynesia",
-        "Adak, United States of America",
-        "Honolulu, United States of America"
-    ],
-    "900": [
-        "Gambier, French Polynesia",
-        "Anchorage, United States of America",
-        "Juneau, United States of America",
-        "Sitka, United States of America",
-        "Metlakatla, United States of America",
-        "Yakutat, United States of America",
-        "Nome, United States of America"
-    ],
-    "960": [
-        "Vancouver, Canada",
-        "Tijuana, Mexico",
-        "Pitcairn, Pitcairn",
-        "Los Angeles, United States of America"
-    ],
-    "1020": [
-        "Edmonton, Canada",
-        "Cambridge Bay, Canada",
-        "Yellowknife, Canada",
-        "Inuvik, Canada",
-        "Creston, Canada",
-        "Dawson Creek, Canada",
-        "Fort Nelson, Canada",
-        "Whitehorse, Canada",
-        "Dawson, Canada",
-        "Mazatlan, Mexico",
-        "Chihuahua, Mexico",
-        "Ojinaga, Mexico",
-        "Hermosillo, Mexico",
-        "Denver, United States of America",
-        "Boise, United States of America",
-        "Phoenix, United States of America"
-    ],
-    "1080": [
-        "Belize, Belize",
-        "Winnipeg, Canada",
-        "Rainy River, Canada",
-        "Resolute, Canada",
-        "Rankin Inlet, Canada",
-        "Regina, Canada",
-        "Swift Current, Canada",
-        "Costa Rica, Costa Rica",
-        "Galapagos, Ecuador",
-        "Guatemala, Guatemala",
-        "Tegucigalpa, Honduras",
-        "Mexico City, Mexico",
-        "Merida, Mexico",
-        "Monterrey, Mexico",
-        "Matamoros, Mexico",
-        "Bahia Banderas, Mexico",
-        "Managua, Nicaragua",
-        "El Salvador, El Salvador",
-        "Chicago, United States of America",
-        "Tell City, Indiana",
-        "Knox, Indiana",
-        "Menominee, United States of America",
-        "Center, North Dakota",
-        "New_Salem, North Dakota",
-        "Beulah, North Dakota"
-    ],
-    "1140": [
-        "Eirunepe, Brazil",
-        "Rio Branco, Brazil",
-        "Nassau, Bahamas",
-        "Toronto, Canada",
-        "Nipigon, Canada",
-        "Thunder Bay, Canada",
-        "Iqaluit, Canada",
-        "Pangnirtung, Canada",
-        "Atikokan, Canada",
-        "Easter, Chile",
-        "Bogota, Colombia",
-        "Havana, Cuba",
-        "Guayaquil, Ecuador",
-        "Port-au-Prince, Haiti",
-        "Jamaica, Jamaica",
-        "Cayman, Cayman Islands",
-        "Cancun, Mexico",
-        "Panama, Panama",
-        "Lima, Peru",
-        "Grand Turk, Turks and Caicos Islands",
-        "New York, United States of America",
-        "Detroit, United States of America",
-        "Louisville, Kentucky",
-        "Monticello, Kentucky",
-        "Indianapolis, Indiana",
-        "Vincennes, Indiana",
-        "Winamac, Indiana",
-        "Marengo, Indiana",
-        "Petersburg, Indiana",
-        "Vevay, Indiana"
-    ],
-    "1200": [
-        "Antigua, Antigua and Barbuda",
-        "Anguilla, Anguilla",
-        "Aruba, Aruba",
-        "Barbados, Barbados",
-        "St Barthelemy, Saint Barthélemy",
-        "Bermuda, Bermuda",
-        "La Paz, Bolivia (Plurinational State of)",
-        "Kralendijk, Bonaire, Sint Eustatius and Saba",
-        "Campo Grande, Brazil",
-        "Cuiaba, Brazil",
-        "Porto Velho, Brazil",
-        "Boa Vista, Brazil",
-        "Manaus, Brazil",
-        "Halifax, Canada",
-        "Glace Bay, Canada",
-        "Moncton, Canada",
-        "Goose Bay, Canada",
-        "Blanc-Sablon, Canada",
-        "Curacao, Curaçao",
-        "Dominica, Dominica",
-        "Santo Domingo, Dominican Republic",
-        "Grenada, Grenada",
-        "Thule, Greenland",
-        "Guadeloupe, Guadeloupe",
-        "Guyana, Guyana",
-        "St Kitts, Saint Kitts and Nevis",
-        "St Lucia, Saint Lucia",
-        "Marigot, Saint Martin (French part)",
-        "Martinique, Martinique",
-        "Montserrat, Montserrat",
-        "Puerto Rico, Puerto Rico",
-        "Lower Princes, Sint Maarten (Dutch part)",
-        "Port of_Spain, Trinidad and Tobago",
-        "St Vincent, Saint Vincent and the Grenadines",
-        "Caracas, Venezuela (Bolivarian Republic of)",
-        "Tortola, Virgin Islands (British)",
-        "St Thomas, Virgin Islands (U.S.)"
-    ],
-    "1260": [
-        "Palmer, Antarctica",
-        "Rothera, Antarctica",
-        "Buenos Aires, Argentina",
-        "Cordoba, Argentina",
-        "Salta, Argentina",
-        "Jujuy, Argentina",
-        "Tucuman, Argentina",
-        "Catamarca, Argentina",
-        "La Rioja, Argentina",
-        "San Juan, Argentina",
-        "Mendoza, Argentina",
-        "San Luis, Argentina",
-        "Rio Gallegos, Argentina",
-        "Ushuaia, Argentina",
-        "Belem, Brazil",
-        "Fortaleza, Brazil",
-        "Recife, Brazil",
-        "Araguaina, Brazil",
-        "Maceio, Brazil",
-        "Bahia, Brazil",
-        "Sao Paulo, Brazil",
-        "Santarem, Brazil",
-        "Santiago, Chile",
-        "Punta Arenas, Chile",
-        "Stanley, Falkland Islands (Malvinas)",
-        "Cayenne, French Guiana",
-        "Nuuk, Greenland",
-        "Miquelon, Saint Pierre and Miquelon",
-        "Asuncion, Paraguay",
-        "Paramaribo, Suriname",
-        "Montevideo, Uruguay"
-    ],
-    "1320": [
-        "Noronha, Brazil",
-        "South Georgia, South Georgia and the South Sandwich Islands"
-    ],
-    "1380": [
-        "Cape Verde, Cabo Verde",
-        "Scoresbysund, Greenland",
-        "Azores, Portugal"
-    ]
-}

apps/ftclock/mkFourTwentyTz.js

@@ -57,6 +57,10 @@ fs.createReadStream(__dirname+'/country.csv')
               zonelist.push(zone.name);
               offsdict[zone.offs] = zonelist;
             }
+            offsets = [];
+            for (o in offsdict) {
+              offsets.unshift(parseInt(o));
+            }
             fs.open("fourTwentyTz.js","w", (err, fd) => {
               if (err) {
                 console.log("Can't open output file");
@@ -65,8 +69,17 @@ fs.createReadStream(__dirname+'/country.csv')
               fs.write(fd, "// Generated by mkFourTwentyTz.js\n", handleWrite);
               fs.write(fd, `// ${Date()}\n`, handleWrite);
               fs.write(fd, "// Data source: https://timezonedb.com/files/timezonedb.csv.zip\n", handleWrite);
-              fs.write(fd, "exports.timezones = ", handleWrite);
+              fs.write(fd, "exports.offsets = ", handleWrite);
-              fs.write(fd, JSON.stringify(offsdict, null, 4), handleWrite);
+              fs.write(fd, JSON.stringify(offsets), handleWrite);
+              fs.write(fd, ";\n", handleWrite);
+              fs.write(fd, "exports.timezones = function(offs) {\n", handleWrite);
+              fs.write(fd, "  switch (offs) {\n", handleWrite);
+              for (o in offsdict) {
+                fs.write(fd, `    case ${o}: return ${JSON.stringify(offsdict[o])};\n`, handleWrite);
+              }
+              fs.write(fd, "    default: return [\"Houston, we have a bug.\"];\n", handleWrite);
+              fs.write(fd, "  };\n", handleWrite);
+              fs.write(fd, "};\n", handleWrite);
               console.log('Done.');
             });
           })