timeZone.html

timeZone.html

<script>

var timeZoneIds = [
  "Africa/Abidjan",
  "Africa/Accra",
  "Africa/Addis_Ababa",
  "Africa/Algiers",
  "Africa/Asmera",
  "Africa/Bamako",
  "Africa/Bangui",
  "Africa/Banjul",
  "Africa/Bissau",
  "Africa/Blantyre",
  "Africa/Brazzaville",
  "Africa/Bujumbura",
  "Africa/Cairo",
  "Africa/Casablanca",
  "Africa/Ceuta",
  "Africa/Conakry",
  "Africa/Dakar",
  "Africa/Djibouti",
  "Africa/Douala",
  "Africa/El_Aaiun",
  "Africa/Freetown",
  "Africa/Gaborone",
  "Africa/Harare",
  "Africa/Johannesburg",
  "Africa/Juba",
  "Africa/Kampala",
  "Africa/Khartoum",
  "Africa/Kigali",
  "Africa/Kinshasa",
  "Africa/Lagos",
  "Africa/Libreville",
  "Africa/Lome",
  "Africa/Luanda",
  "Africa/Lubumbashi",
  "Africa/Lusaka",
  "Africa/Malabo",
  "Africa/Maputo",
  "Africa/Maseru",
  "Africa/Mbabane",
  "Africa/Mogadishu",
  "Africa/Monrovia",
  "Africa/Nairobi",
  "Africa/Ndjamena",
  "Africa/Niamey",
  "Africa/Nouakchott",
  "Africa/Ouagadougou",
  "Africa/Sao_Tome",
  "Africa/Tripoli",
  "Africa/Tunis",
  "Africa/Windhoek",
  "America/Adak",
  "America/Anchorage",
  "America/Anguilla",
  "America/Antigua",
  "America/Araguaina",
  "America/Aruba",
  "America/Asuncion",
  "America/Bahia",
  "America/Bahia_Banderas",
  "America/Barbados",
  "America/Belem",
  "America/Belize",
  "America/Boa_Vista",
  "America/Bogota",
  "America/Boise",
  "America/Buenos_Aires",
  "America/Cambridge_Bay",
  "America/Campo_Grande",
  "America/Cancun",
  "America/Caracas",
  "America/Catamarca",
  "America/Cayenne",
  "America/Cayman",
  "America/Chicago",
  "America/Chihuahua",
  "America/Coral_Harbour",
  "America/Cordoba",
  "America/Costa_Rica",
  "America/Cuiaba",
  "America/Curacao",
  "America/Danmarkshavn",
  "America/Dawson",
  "America/Dawson_Creek",
  "America/Denver",
  "America/Detroit",
  "America/Dominica",
  "America/Edmonton",
  "America/Eirunepe",
  "America/El_Salvador",
  "America/Fortaleza",
  "America/Glace_Bay",
  "America/Godthab",
  "America/Goose_Bay",
  "America/Grand_Turk",
  "America/Grenada",
  "America/Guadeloupe",
  "America/Guatemala",
  "America/Guayaquil",
  "America/Guyana",
  "America/Halifax",
  "America/Havana",
  "America/Hermosillo",
  "America/Indianapolis",
  "America/Inuvik",
  "America/Iqaluit",
  "America/Jamaica",
  "America/Jujuy",
  "America/Juneau",
  "America/La_Paz",
  "America/Lima",
  "America/Los_Angeles",
  "America/Louisville",
  "America/Maceio",
  "America/Managua",
  "America/Manaus",
  "America/Marigot",
  "America/Martinique",
  "America/Matamoros",
  "America/Mazatlan",
  "America/Mendoza",
  "America/Menominee",
  "America/Merida",
  "America/Metlakatla",
  "America/Mexico_City",
  "America/Miquelon",
  "America/Moncton",
  "America/Monterrey",
  "America/Montevideo",
  "America/Montreal",
  "America/Montserrat",
  "America/Nassau",
  "America/New_York",
  "America/Nipigon",
  "America/Nome",
  "America/Noronha",
  "America/Ojinaga",
  "America/Panama",
  "America/Pangnirtung",
  "America/Paramaribo",
  "America/Phoenix",
  "America/Porto_Velho",
  "America/Puerto_Rico",
  "America/Rainy_River",
  "America/Rankin_Inlet",
  "America/Recife",
  "America/Regina",
  "America/Resolute",
  "America/Rio_Branco",
  "America/Santa_Isabel",
  "America/Santarem",
  "America/Santiago",
  "America/Santo_Domingo",
  "America/Sao_Paulo",
  "America/Scoresbysund",
  "America/Shiprock",
  "America/Sitka",
  "America/St_Barthelemy",
  "America/St_Johns",
  "America/St_Kitts",
  "America/St_Lucia",
  "America/St_Thomas",
  "America/St_Vincent",
  "America/Swift_Current",
  "America/Tegucigalpa",
  "America/Thule",
  "America/Thunder_Bay",
  "America/Tijuana",
  "America/Toronto",
  "America/Tortola",
  "America/Vancouver",
  "America/Whitehorse",
  "America/Winnipeg",
  "America/Yakutat",
  "America/Yellowknife",
  "Antarctica/Casey",
  "Antarctica/Davis",
  "Antarctica/Macquarie",
  "Antarctica/Mawson",
  "Antarctica/Palmer",
  "Antarctica/Rothera",
  "Antarctica/South_Pole",
  "Antarctica/Syowa",
  "Antarctica/Vostok",
  "Arctic/Longyearbyen",
  "Asia/Aden",
  "Asia/Almaty",
  "Asia/Amman",
  "Asia/Anadyr",
  "Asia/Aqtau",
  "Asia/Aqtobe",
  "Asia/Ashgabat",
  "Asia/Baghdad",
  "Asia/Bahrain",
  "Asia/Baku",
  "Asia/Bangkok",
  "Asia/Beirut",
  "Asia/Bishkek",
  "Asia/Brunei",
  "Asia/Calcutta",
  "Asia/Choibalsan",
  "Asia/Chongqing",
  "Asia/Colombo",
  "Asia/Damascus",
  "Asia/Dhaka",
  "Asia/Dili",
  "Asia/Dubai",
  "Asia/Dushanbe",
  "Asia/Gaza",
  "Asia/Harbin",
  "Asia/Hebron",
  "Asia/Hong_Kong",
  "Asia/Hovd",
  "Asia/Irkutsk",
  "Asia/Jakarta",
  "Asia/Jayapura",
  "Asia/Jerusalem",
  "Asia/Kabul",
  "Asia/Kamchatka",
  "Asia/Karachi",
  "Asia/Kashgar",
  "Asia/Katmandu",
  "Asia/Krasnoyarsk",
  "Asia/Kuala_Lumpur",
  "Asia/Kuching",
  "Asia/Kuwait",
  "Asia/Macau",
  "Asia/Magadan",
  "Asia/Makassar",
  "Asia/Manila",
  "Asia/Muscat",
  "Asia/Nicosia",
  "Asia/Novokuznetsk",
  "Asia/Novosibirsk",
  "Asia/Omsk",
  "Asia/Oral",
  "Asia/Phnom_Penh",
  "Asia/Pontianak",
  "Asia/Pyongyang",
  "Asia/Qatar",
  "Asia/Qyzylorda",
  "Asia/Rangoon",
  "Asia/Riyadh",
  "Asia/Saigon",
  "Asia/Sakhalin",
  "Asia/Samarkand",
  "Asia/Seoul",
  "Asia/Shanghai",
  "Asia/Singapore",
  "Asia/Taipei",
  "Asia/Tashkent",
  "Asia/Tbilisi",
  "Asia/Tehran",
  "Asia/Thimphu",
  "Asia/Tokyo",
  "Asia/Ulaanbaatar",
  "Asia/Urumqi",
  "Asia/Vientiane",
  "Asia/Vladivostok",
  "Asia/Yakutsk",
  "Asia/Yekaterinburg",
  "Asia/Yerevan",
  "Atlantic/Azores",
  "Atlantic/Bermuda",
  "Atlantic/Canary",
  "Atlantic/Cape_Verde",
  "Atlantic/Faeroe",
  "Atlantic/Madeira",
  "Atlantic/Reykjavik",
  "Atlantic/South_Georgia",
  "Atlantic/St_Helena",
  "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",
  "Etc/GMT",
  "Etc/UTC",
  "Europe/Amsterdam",
  "Europe/Andorra",
  "Europe/Athens",
  "Europe/Belgrade",
  "Europe/Berlin",
  "Europe/Bratislava",
  "Europe/Brussels",
  "Europe/Bucharest",
  "Europe/Budapest",
  "Europe/Chisinau",
  "Europe/Copenhagen",
  "Europe/Dublin",
  "Europe/Gibraltar",
  "Europe/Guernsey",
  "Europe/Helsinki",
  "Europe/Istanbul",
  "Europe/Jersey",
  "Europe/Kaliningrad",
  "Europe/Kiev",
  "Europe/Lisbon",
  "Europe/Ljubljana",
  "Europe/London",
  "Europe/Luxembourg",
  "Europe/Madrid",
  "Europe/Malta",
  "Europe/Mariehamn",
  "Europe/Minsk",
  "Europe/Monaco",
  "Europe/Moscow",
  "Europe/Oslo",
  "Europe/Paris",
  "Europe/Podgorica",
  "Europe/Prague",
  "Europe/Riga",
  "Europe/Rome",
  "Europe/Samara",
  "Europe/San_Marino",
  "Europe/Sarajevo",
  "Europe/Simferopol",
  "Europe/Skopje",
  "Europe/Sofia",
  "Europe/Stockholm",
  "Europe/Tallinn",
  "Europe/Tirane",
  "Europe/Uzhgorod",
  "Europe/Vaduz",
  "Europe/Vatican",
  "Europe/Vienna",
  "Europe/Vilnius",
  "Europe/Volgograd",
  "Europe/Warsaw",
  "Europe/Zagreb",
  "Europe/Zaporozhye",
  "Europe/Zurich",
  "GMT",
  "Indian/Antananarivo",
  "Indian/Chagos",
  "Indian/Christmas",
  "Indian/Cocos",
  "Indian/Comoro",
  "Indian/Kerguelen",
  "Indian/Mahe",
  "Indian/Maldives",
  "Indian/Mauritius",
  "Indian/Mayotte",
  "Indian/Reunion",
  "Pacific/Apia",
  "Pacific/Auckland",
  "Pacific/Chatham",
  "Pacific/Easter",
  "Pacific/Efate",
  "Pacific/Enderbury",
  "Pacific/Fakaofo",
  "Pacific/Fiji",
  "Pacific/Funafuti",
  "Pacific/Galapagos",
  "Pacific/Gambier",
  "Pacific/Guadalcanal",
  "Pacific/Guam",
  "Pacific/Honolulu",
  "Pacific/Johnston",
  "Pacific/Kiritimati",
  "Pacific/Kosrae",
  "Pacific/Kwajalein",
  "Pacific/Majuro",
  "Pacific/Marquesas",
  "Pacific/Midway",
  "Pacific/Nauru",
  "Pacific/Niue",
  "Pacific/Norfolk",
  "Pacific/Noumea",
  "Pacific/Pago_Pago",
  "Pacific/Palau",
  "Pacific/Pitcairn",
  "Pacific/Ponape",
  "Pacific/Port_Moresby",
  "Pacific/Rarotonga",
  "Pacific/Saipan",
  "Pacific/Tahiti",
  "Pacific/Tarawa",
  "Pacific/Tongatapu",
  "Pacific/Truk",
  "Pacific/Wake",
  "Pacific/Wallis",
  "UTC"
];

var timeZones = {
  "0": "UTC",
  "3600": "Africa/Tunis",
  "7200": "Asia/Hebron",
  "10800": "Indian/Mayotte",
  "14400": "Indian/Reunion",
  "16200": "Asia/Kabul",
  "18000": "Indian/Maldives",
  "19800": "Asia/Colombo",
  "20700": "Asia/Katmandu",
  "21600": "Indian/Chagos",
  "23400": "Indian/Cocos",
  "25200": "Indian/Christmas",
  "28800": "Australia/Perth",
  "31500": "Australia/Eucla",
  "32400": "Pacific/Palau",
  "34200": "Australia/Darwin",
  "36000": "Pacific/Truk",
  "39600": "Pacific/Ponape",
  "41400": "Pacific/Norfolk",
  "43200": "Pacific/Wallis",
  "46800": "Pacific/Tongatapu",
  "50400": "Pacific/Kiritimati",
  "7200,1351386000000,3600": "Europe/Zurich",
  "3600,1346547600000,7200": "Africa/Windhoek",
  "-32400,1352026800000,-36000": "America/Adak",
  "-28800,1352023200000,-32400": "America/Yakutat",
  "-14400": "America/Tortola",
  "-10800": "Antarctica/Rothera",
  "-14400,1349049600000,-10800": "America/Asuncion",
  "-10800,1350788400000,-7200": "America/Sao_Paulo",
  "-18000,1351407600000,-21600": "America/Monterrey",
  "-21600": "Pacific/Galapagos",
  "-18000": "America/Panama",
  "-21600,1352016000000,-25200": "America/Yellowknife",
  "-14400,1350792000000,-10800": "America/Cuiaba",
  "-16200": "America/Caracas",
  "-18000,1352012400000,-21600": "America/Winnipeg",
  "-21600,1351411200000,-25200": "America/Mazatlan",
  "-25200,1352019600000,-28800": "America/Whitehorse",
  "-25200": "America/Phoenix",
  "-14400,1352008800000,-18000": "America/Toronto",
  "-10800,1352005200000,-14400": "Atlantic/Bermuda",
  "-7200,1351386000000,-10800": "America/Godthab",
  "-14400,1351400400000,-18000": "America/Havana",
  "-28800": "Pacific/Pitcairn",
  "-7200,1352001600000,-10800": "America/Miquelon",
  "-10800,1349049600000,-7200": "America/Montevideo",
  "-7200": "Atlantic/South_Georgia",
  "-25200,1351414800000,-28800": "America/Santa_Isabel",
  "-14400,1350187200000,-10800": "Antarctica/Palmer",
  "0,1351386000000,-3600": "Atlantic/Azores",
  "-9000,1352003400000,-12600": "America/St_Johns",
  "43200,1348927200000,46800": "Pacific/Auckland",
  "10800,1351202400000,7200": "Asia/Amman",
  "18000,1351382400000,14400": "Asia/Baku",
  "10800,1351371600000,7200": "Asia/Beirut",
  "10800,1351198800000,7200": "Asia/Damascus",
  "10800,1348354800000,7200": "Asia/Jerusalem",
  "10800,1351386000000,7200": "Europe/Zaporozhye",
  "16200,1348169400000,12600": "Asia/Tehran",
  "18000,1351375200000,14400": "Asia/Yerevan",
  "3600,1351386000000,0": "Europe/London",
  "-3600": "Atlantic/Cape_Verde",
  "-14400,1346565600000,-10800": "Atlantic/Stanley",
  "34200,1349541000000,37800": "Australia/Broken_Hill",
  "36000,1349539200000,39600": "Australia/Sydney",
  "37800,1349537400000,39600": "Australia/Lord_Howe",
  "45900,1348927200000,49500": "Pacific/Chatham",
  "-21600,1350187200000,-18000": "Pacific/Easter",
  "-36000": "Pacific/Tahiti",
  "-32400": "Pacific/Gambier",
  "-34200": "Pacific/Marquesas",
  "-39600": "Pacific/Pago_Pago"
};

var TimeZoneUtils = {
  formatsCache: {},
  getTimeZoneOffset: function (timeZoneId, timeStamp) {
    if (timeZoneId === null) {
      var date = new Date(timeStamp);
      return date.getTimezoneOffset() * -60;
    } else {
      var formatsCache = TimeZoneUtils.formatsCache;
      var x = formatsCache[timeZoneId];
      if (x === undefined) {
        var options = {hour12: false, day: "2-digit", hour: "2-digit", minute: "2-digit", second: "2-digit", timeZone: timeZoneId};
        x = new Intl.DateTimeFormat("en", options);
        formatsCache[timeZoneId] = x;
      }
      var date = new Date(timeStamp);
      var s = x.format(date);
      var m = s.match(/^(\d\d)\s*(\d\d)\:(\d\d):(\d\d)$/);
      if (!m) {
        throw new Error(s);//!
      }
      var gmtTime = ((date.getUTCDate() * 24 + date.getUTCHours()) * 60 + date.getUTCMinutes()) * 60 + date.getUTCSeconds();
      var localTime = ((Number(m[1]) * 24 + Number(m[2])) * 60 + Number(m[3])) * 60 + Number(m[4]);
      var offset = localTime - gmtTime;
      return offset;
    }
  },
  getTimeZoneTransitions: function (timeZoneId) {
    var to = 1356998400000;
    var from = to - 0.5 * 366 * 86400 * 1000;
    var step = 86400000 * 28;
    var lastOffset = -1;
    var transitions = "";
    while ((from += step) < to) {
      var offset = TimeZoneUtils.getTimeZoneOffset(timeZoneId, from);
      if (lastOffset === -1) {
        lastOffset = offset;
        transitions += String(offset);
      }
      if (offset !== lastOffset) {
        // binary search
        var a = from - step;
        var b = from;
        while (b - a > 1) {
          var m = a + Math.floor((b - a) / 2);
          if (TimeZoneUtils.getTimeZoneOffset(timeZoneId, m) === lastOffset) {
            a = m;
          } else {
            b = m;
          }
        }
        transitions += "," + String(b) + "," + String(offset);
        lastOffset = offset;
      }
    }
    return transitions;
  },
  offsetToString: function (offset) {
    var a = Math.abs(offset);
    var hours = Math.floor(a / 3600);
    var minutes = Math.floor((a % 60) / 60);
    return "GMT" + (offset < 0 ? "-" : "+") + (hours < 10 ? "0" : "") + hours + (minutes < 10 ? "0" : "") + minutes;
  },
  getTimeZone: function () {
    return timeZones[TimeZoneUtils.getTimeZoneTransitions(null)] || TimeZoneUtils.offsetToString(TimeZoneUtils.getTimeZoneOffset(null, new Date().getTime()));
  },
  getTimeZonesMap: function () {
    var map = {};
    var i = -1;
    while (++i < timeZoneIds.length) {
      var id = timeZoneIds[i];
      try {
        var s = TimeZoneUtils.getTimeZoneTransitions(id);
        map[s] = id;
      } catch (e) {
        if (e instanceof RangeError) {
          // Unsupported time zone
          console.log(String(e.message));
        } else {
          throw e;
        }
      }
    }
    return map;
  }
};

console.log(TimeZoneUtils.getTimeZone());

</script>