references/rails-timezones.json

{
  "$source": "ActiveSupport::TimeZone::MAPPING (Rails 7.0.3.1, activesupport/lib/active_support/values/time_zone.rb L31-L183).",
  "$validation": "Workflow's `timezone` column must equal one of the keys in `mapping` (i.e. one of `friendly_names`). Validated by `validates :timezone, inclusion: ActiveSupport::TimeZone.all.map(&:name)` (workflow/rails/app/models/workflow/setup.rb L32). At runtime, Rails resolves the friendly name to the IANA value via `ActiveSupport::TimeZone.find_tzinfo(name).name` and appends it to the Rufus cron string (workflow/rails/app/models/workflow.rb L335-336).",
  "$gotchas": [
    "Bare IANA names like `America/New_York` and `Europe/London` ARE NOT in this list and FAIL validation, even though Rufus would happily accept them. Convert IANA -> friendly name before persisting. `UTC` is valid because Rails also exposes it as a friendly name.",
    "Some friendly names alias to the same IANA zone (e.g. `London` and `Edinburgh` both map to `Europe/London`). Either name is valid; pick the one your users recognize.",
    "`UTC` here is the friendly name. Its IANA value is `Etc/UTC`."
  ],
  "iana_to_friendly_recommendations": {
    "America/New_York": "Eastern Time (US & Canada)",
    "America/Chicago": "Central Time (US & Canada)",
    "America/Denver": "Mountain Time (US & Canada)",
    "America/Los_Angeles": "Pacific Time (US & Canada)",
    "America/Phoenix": "Arizona",
    "America/Anchorage": "Alaska",
    "America/Juneau": "Alaska",
    "Pacific/Honolulu": "Hawaii",
    "America/Halifax": "Atlantic Time (Canada)",
    "America/St_Johns": "Newfoundland",
    "Europe/London": "London",
    "Europe/Dublin": "Dublin",
    "Europe/Berlin": "Berlin",
    "Europe/Paris": "Paris",
    "Europe/Madrid": "Madrid",
    "Europe/Rome": "Rome",
    "Europe/Amsterdam": "Amsterdam",
    "Europe/Brussels": "Brussels",
    "Europe/Stockholm": "Stockholm",
    "Europe/Vienna": "Vienna",
    "Europe/Athens": "Athens",
    "Europe/Helsinki": "Helsinki",
    "Europe/Istanbul": "Istanbul",
    "Europe/Moscow": "Moscow",
    "Europe/Warsaw": "Warsaw",
    "Europe/Bucharest": "Bucharest",
    "Africa/Cairo": "Cairo",
    "Africa/Johannesburg": "Pretoria",
    "Asia/Jerusalem": "Jerusalem",
    "Asia/Dubai": "Abu Dhabi",
    "Asia/Muscat": "Muscat",
    "Asia/Karachi": "Karachi",
    "Asia/Kolkata": "Kolkata",
    "Asia/Calcutta": "Kolkata",
    "Asia/Bangkok": "Bangkok",
    "Asia/Singapore": "Singapore",
    "Asia/Hong_Kong": "Hong Kong",
    "Asia/Shanghai": "Beijing",
    "Asia/Taipei": "Taipei",
    "Asia/Tokyo": "Tokyo",
    "Asia/Seoul": "Seoul",
    "Australia/Sydney": "Sydney",
    "Australia/Melbourne": "Melbourne",
    "Australia/Brisbane": "Brisbane",
    "Australia/Perth": "Perth",
    "Australia/Adelaide": "Adelaide",
    "Pacific/Auckland": "Auckland",
    "Pacific/Fiji": "Fiji",
    "Etc/UTC": "UTC",
    "UTC": "UTC",
    "GMT": "UTC",
    "Z": "UTC"
  },
  "mapping": {
    "International Date Line West": "Etc/GMT+12",
    "Midway Island": "Pacific/Midway",
    "American Samoa": "Pacific/Pago_Pago",
    "Hawaii": "Pacific/Honolulu",
    "Alaska": "America/Juneau",
    "Pacific Time (US & Canada)": "America/Los_Angeles",
    "Tijuana": "America/Tijuana",
    "Mountain Time (US & Canada)": "America/Denver",
    "Arizona": "America/Phoenix",
    "Chihuahua": "America/Chihuahua",
    "Mazatlan": "America/Mazatlan",
    "Central Time (US & Canada)": "America/Chicago",
    "Saskatchewan": "America/Regina",
    "Guadalajara": "America/Mexico_City",
    "Mexico City": "America/Mexico_City",
    "Monterrey": "America/Monterrey",
    "Central America": "America/Guatemala",
    "Eastern Time (US & Canada)": "America/New_York",
    "Indiana (East)": "America/Indiana/Indianapolis",
    "Bogota": "America/Bogota",
    "Lima": "America/Lima",
    "Quito": "America/Lima",
    "Atlantic Time (Canada)": "America/Halifax",
    "Caracas": "America/Caracas",
    "La Paz": "America/La_Paz",
    "Santiago": "America/Santiago",
    "Newfoundland": "America/St_Johns",
    "Brasilia": "America/Sao_Paulo",
    "Buenos Aires": "America/Argentina/Buenos_Aires",
    "Montevideo": "America/Montevideo",
    "Georgetown": "America/Guyana",
    "Puerto Rico": "America/Puerto_Rico",
    "Greenland": "America/Godthab",
    "Mid-Atlantic": "Atlantic/South_Georgia",
    "Azores": "Atlantic/Azores",
    "Cape Verde Is.": "Atlantic/Cape_Verde",
    "Dublin": "Europe/Dublin",
    "Edinburgh": "Europe/London",
    "Lisbon": "Europe/Lisbon",
    "London": "Europe/London",
    "Casablanca": "Africa/Casablanca",
    "Monrovia": "Africa/Monrovia",
    "UTC": "Etc/UTC",
    "Belgrade": "Europe/Belgrade",
    "Bratislava": "Europe/Bratislava",
    "Budapest": "Europe/Budapest",
    "Ljubljana": "Europe/Ljubljana",
    "Prague": "Europe/Prague",
    "Sarajevo": "Europe/Sarajevo",
    "Skopje": "Europe/Skopje",
    "Warsaw": "Europe/Warsaw",
    "Zagreb": "Europe/Zagreb",
    "Brussels": "Europe/Brussels",
    "Copenhagen": "Europe/Copenhagen",
    "Madrid": "Europe/Madrid",
    "Paris": "Europe/Paris",
    "Amsterdam": "Europe/Amsterdam",
    "Berlin": "Europe/Berlin",
    "Bern": "Europe/Zurich",
    "Zurich": "Europe/Zurich",
    "Rome": "Europe/Rome",
    "Stockholm": "Europe/Stockholm",
    "Vienna": "Europe/Vienna",
    "West Central Africa": "Africa/Algiers",
    "Bucharest": "Europe/Bucharest",
    "Cairo": "Africa/Cairo",
    "Helsinki": "Europe/Helsinki",
    "Kyiv": "Europe/Kiev",
    "Riga": "Europe/Riga",
    "Sofia": "Europe/Sofia",
    "Tallinn": "Europe/Tallinn",
    "Vilnius": "Europe/Vilnius",
    "Athens": "Europe/Athens",
    "Istanbul": "Europe/Istanbul",
    "Minsk": "Europe/Minsk",
    "Jerusalem": "Asia/Jerusalem",
    "Harare": "Africa/Harare",
    "Pretoria": "Africa/Johannesburg",
    "Kaliningrad": "Europe/Kaliningrad",
    "Moscow": "Europe/Moscow",
    "St. Petersburg": "Europe/Moscow",
    "Volgograd": "Europe/Volgograd",
    "Samara": "Europe/Samara",
    "Kuwait": "Asia/Kuwait",
    "Riyadh": "Asia/Riyadh",
    "Nairobi": "Africa/Nairobi",
    "Baghdad": "Asia/Baghdad",
    "Tehran": "Asia/Tehran",
    "Abu Dhabi": "Asia/Muscat",
    "Muscat": "Asia/Muscat",
    "Baku": "Asia/Baku",
    "Tbilisi": "Asia/Tbilisi",
    "Yerevan": "Asia/Yerevan",
    "Kabul": "Asia/Kabul",
    "Ekaterinburg": "Asia/Yekaterinburg",
    "Islamabad": "Asia/Karachi",
    "Karachi": "Asia/Karachi",
    "Tashkent": "Asia/Tashkent",
    "Chennai": "Asia/Kolkata",
    "Kolkata": "Asia/Kolkata",
    "Mumbai": "Asia/Kolkata",
    "New Delhi": "Asia/Kolkata",
    "Kathmandu": "Asia/Kathmandu",
    "Astana": "Asia/Dhaka",
    "Dhaka": "Asia/Dhaka",
    "Sri Jayawardenepura": "Asia/Colombo",
    "Almaty": "Asia/Almaty",
    "Novosibirsk": "Asia/Novosibirsk",
    "Rangoon": "Asia/Rangoon",
    "Bangkok": "Asia/Bangkok",
    "Hanoi": "Asia/Bangkok",
    "Jakarta": "Asia/Jakarta",
    "Krasnoyarsk": "Asia/Krasnoyarsk",
    "Beijing": "Asia/Shanghai",
    "Chongqing": "Asia/Chongqing",
    "Hong Kong": "Asia/Hong_Kong",
    "Urumqi": "Asia/Urumqi",
    "Kuala Lumpur": "Asia/Kuala_Lumpur",
    "Singapore": "Asia/Singapore",
    "Taipei": "Asia/Taipei",
    "Perth": "Australia/Perth",
    "Irkutsk": "Asia/Irkutsk",
    "Ulaanbaatar": "Asia/Ulaanbaatar",
    "Seoul": "Asia/Seoul",
    "Osaka": "Asia/Tokyo",
    "Sapporo": "Asia/Tokyo",
    "Tokyo": "Asia/Tokyo",
    "Yakutsk": "Asia/Yakutsk",
    "Darwin": "Australia/Darwin",
    "Adelaide": "Australia/Adelaide",
    "Canberra": "Australia/Melbourne",
    "Melbourne": "Australia/Melbourne",
    "Sydney": "Australia/Sydney",
    "Brisbane": "Australia/Brisbane",
    "Hobart": "Australia/Hobart",
    "Vladivostok": "Asia/Vladivostok",
    "Guam": "Pacific/Guam",
    "Port Moresby": "Pacific/Port_Moresby",
    "Magadan": "Asia/Magadan",
    "Srednekolymsk": "Asia/Srednekolymsk",
    "Solomon Is.": "Pacific/Guadalcanal",
    "New Caledonia": "Pacific/Noumea",
    "Fiji": "Pacific/Fiji",
    "Kamchatka": "Asia/Kamchatka",
    "Marshall Is.": "Pacific/Majuro",
    "Auckland": "Pacific/Auckland",
    "Wellington": "Pacific/Auckland",
    "Nuku'alofa": "Pacific/Tongatapu",
    "Tokelau Is.": "Pacific/Fakaofo",
    "Chatham Is.": "Pacific/Chatham",
    "Samoa": "Pacific/Apia"
  }
}