Timezone conversions

[drewish]

I spent some time using a .Net timezone conversion library to convert its list of Windows timezones into a mapping of Windows to IANA timezones, then did the munging to get the Windows names into Xero's format (windows_tz_name.upcase.tr('. -', '')).

Here's the hash:

# Maps Zero's time zone names (`windows_tz_name.upcase.tr('. -', '')`) to the
# IANA time zone names.
TIME_ZONES = {
  "AFGHANISTANSTANDARDTIME" => "Asia/Kabul", "ALASKANSTANDARDTIME" => "America/Anchorage",
  "ALEUTIANSTANDARDTIME" => "America/Adak", "ALTAISTANDARDTIME" => "Asia/Barnaul",
  "ARABSTANDARDTIME" => "Asia/Riyadh", "ARABIANSTANDARDTIME" => "Asia/Dubai", "ARABICSTANDARDTIME" => "Asia/Baghdad",
  "ARGENTINASTANDARDTIME" => "America/Argentina/Buenos_Aires", "ASTRAKHANSTANDARDTIME" => "Europe/Astrakhan",
  "ATLANTICSTANDARDTIME" => "America/Halifax", "AUSCENTRALSTANDARDTIME" => "Australia/Darwin",
  "AUSCENTRALWSTANDARDTIME" => "Australia/Eucla", "AUSEASTERNSTANDARDTIME" => "Australia/Sydney",
  "AZERBAIJANSTANDARDTIME" => "Asia/Baku", "AZORESSTANDARDTIME" => "Atlantic/Azores",
  "BAHIASTANDARDTIME" => "America/Bahia", "BANGLADESHSTANDARDTIME" => "Asia/Dhaka",
  "BELARUSSTANDARDTIME" => "Europe/Minsk", "BOUGAINVILLESTANDARDTIME" => "Pacific/Bougainville",
  "CANADACENTRALSTANDARDTIME" => "America/Regina", "CAPEVERDESTANDARDTIME" => "Atlantic/Cape_Verde",
  "CAUCASUSSTANDARDTIME" => "Asia/Yerevan", "CENAUSTRALIASTANDARDTIME" => "Australia/Adelaide",
  "CENTRALAMERICASTANDARDTIME" => "America/Guatemala", "CENTRALASIASTANDARDTIME" => "Asia/Almaty",
  "CENTRALBRAZILIANSTANDARDTIME" => "America/Cuiaba", "CENTRALEUROPESTANDARDTIME" => "Europe/Budapest",
  "CENTRALEUROPEANSTANDARDTIME" => "Europe/Warsaw", "CENTRALPACIFICSTANDARDTIME" => "Pacific/Guadalcanal",
  "CENTRALSTANDARDTIME" => "America/Chicago", "CENTRALSTANDARDTIME(MEXICO)" => "America/Mexico_City",
  "CHATHAMISLANDSSTANDARDTIME" => "Pacific/Chatham", "CHINASTANDARDTIME" => "Asia/Shanghai",
  "CUBASTANDARDTIME" => "America/Havana", "DATELINESTANDARDTIME" => "Etc/GMT+12",
  "EAFRICASTANDARDTIME" => "Africa/Nairobi", "EAUSTRALIASTANDARDTIME" => "Australia/Brisbane",
  "EEUROPESTANDARDTIME" => "Europe/Chisinau", "ESOUTHAMERICASTANDARDTIME" => "America/Sao_Paulo",
  "EASTERISLANDSTANDARDTIME" => "Pacific/Easter", "EASTERNSTANDARDTIME" => "America/New_York",
  "EASTERNSTANDARDTIME(MEXICO)" => "America/Cancun", "EGYPTSTANDARDTIME" => "Africa/Cairo",
  "EKATERINBURGSTANDARDTIME" => "Asia/Yekaterinburg", "FIJISTANDARDTIME" => "Pacific/Fiji",
  "FLESTANDARDTIME" => "Europe/Kiev", "GEORGIANSTANDARDTIME" => "Asia/Tbilisi", "GMTSTANDARDTIME" => "Europe/London",
  "GREENLANDSTANDARDTIME" => "America/Godthab", "GREENWICHSTANDARDTIME" => "Atlantic/Reykjavik",
  "GTBSTANDARDTIME" => "Europe/Bucharest", "HAITISTANDARDTIME" => "America/Port-au-Prince",
  "HAWAIIANSTANDARDTIME" => "Pacific/Honolulu", "INDIASTANDARDTIME" => "Asia/Kolkata",
  "IRANSTANDARDTIME" => "Asia/Tehran", "ISRAELSTANDARDTIME" => "Asia/Jerusalem",
  "JORDANSTANDARDTIME" => "Asia/Amman", "KALININGRADSTANDARDTIME" => "Europe/Kaliningrad",
  "KAMCHATKASTANDARDTIME" => "Asia/Kamchatka", "KOREASTANDARDTIME" => "Asia/Seoul",
  "LIBYASTANDARDTIME" => "Africa/Tripoli", "LINEISLANDSSTANDARDTIME" => "Pacific/Kiritimati",
  "LORDHOWESTANDARDTIME" => "Australia/Lord_Howe", "MAGADANSTANDARDTIME" => "Asia/Magadan",
  "MAGALLANESSTANDARDTIME" => "America/Punta_Arenas", "MARQUESASSTANDARDTIME" => "Pacific/Marquesas",
  "MAURITIUSSTANDARDTIME" => "Indian/Mauritius", "MIDATLANTICSTANDARDTIME" => "Etc/GMT+2",
  "MIDDLEEASTSTANDARDTIME" => "Asia/Beirut", "MONTEVIDEOSTANDARDTIME" => "America/Montevideo",
  "MOROCCOSTANDARDTIME" => "Africa/Casablanca", "MOUNTAINSTANDARDTIME" => "America/Denver",
  "MOUNTAINSTANDARDTIME(MEXICO)" => "America/Chihuahua", "MYANMARSTANDARDTIME" => "Asia/Yangon",
  "NCENTRALASIASTANDARDTIME" => "Asia/Novosibirsk", "NAMIBIASTANDARDTIME" => "Africa/Windhoek",
  "NEPALSTANDARDTIME" => "Asia/Kathmandu", "NEWZEALANDSTANDARDTIME" => "Pacific/Auckland",
  "NEWFOUNDLANDSTANDARDTIME" => "America/St_Johns", "NORFOLKSTANDARDTIME" => "Pacific/Norfolk",
  "NORTHASIAEASTSTANDARDTIME" => "Asia/Irkutsk", "NORTHASIASTANDARDTIME" => "Asia/Krasnoyarsk",
  "NORTHKOREASTANDARDTIME" => "Asia/Pyongyang", "OMSKSTANDARDTIME" => "Asia/Omsk",
  "PACIFICSASTANDARDTIME" => "America/Santiago", "PACIFICSTANDARDTIME" => "America/Los_Angeles",
  "PACIFICSTANDARDTIME(MEXICO)" => "America/Tijuana", "PAKISTANSTANDARDTIME" => "Asia/Karachi",
  "PARAGUAYSTANDARDTIME" => "America/Asuncion", "ROMANCESTANDARDTIME" => "Europe/Paris",
  "RUSSIATIMEZONE10" => "Asia/Srednekolymsk", "RUSSIATIMEZONE11" => "Asia/Kamchatka",
  "RUSSIATIMEZONE3" => "Europe/Samara", "RUSSIANSTANDARDTIME" => "Europe/Moscow",
  "SAEASTERNSTANDARDTIME" => "America/Cayenne", "SAPACIFICSTANDARDTIME" => "America/Bogota",
  "SAWESTERNSTANDARDTIME" => "America/La_Paz", "SAINTPIERRESTANDARDTIME" => "America/Miquelon",
  "SAKHALINSTANDARDTIME" => "Asia/Sakhalin", "SAMOASTANDARDTIME" => "Pacific/Apia",
  "SAOTOMESTANDARDTIME" => "Africa/Sao_Tome", "SARATOVSTANDARDTIME" => "Europe/Saratov",
  "SEASIASTANDARDTIME" => "Asia/Bangkok", "SINGAPORESTANDARDTIME" => "Asia/Singapore",
  "SOUTHAFRICASTANDARDTIME" => "Africa/Johannesburg", "SRILANKASTANDARDTIME" => "Asia/Colombo",
  "SUDANSTANDARDTIME" => "Africa/Khartoum", "SYRIASTANDARDTIME" => "Asia/Damascus",
  "TAIPEISTANDARDTIME" => "Asia/Taipei", "TASMANIASTANDARDTIME" => "Australia/Hobart",
  "TOCANTINSSTANDARDTIME" => "America/Araguaina", "TOKYOSTANDARDTIME" => "Asia/Tokyo",
  "TOMSKSTANDARDTIME" => "Asia/Tomsk", "TONGASTANDARDTIME" => "Pacific/Tongatapu",
  "TRANSBAIKALSTANDARDTIME" => "Asia/Chita", "TURKEYSTANDARDTIME" => "Europe/Istanbul",
  "TURKSANDCAICOSSTANDARDTIME" => "America/Grand_Turk", "ULAANBAATARSTANDARDTIME" => "Asia/Ulaanbaatar",
  "USEASTERNSTANDARDTIME" => "America/Indiana/Indianapolis", "USMOUNTAINSTANDARDTIME" => "America/Phoenix",
  "UTC" => "Etc/UTC", "UTC+12" => "Etc/GMT+12", "UTC+13" => "Etc/GMT+13", "UTC02" => "Etc/GMT-2",
  "UTC08" => "Etc/GMT-8", "UTC09" => "Etc/GMT-9", "UTC11" => "Etc/GMT-11",
  "VENEZUELASTANDARDTIME" => "America/Caracas", "VLADIVOSTOKSTANDARDTIME" => "Asia/Vladivostok",
  "WAUSTRALIASTANDARDTIME" => "Australia/Perth", "WCENTRALAFRICASTANDARDTIME" => "Africa/Lagos",
  "WEUROPESTANDARDTIME" => "Europe/Berlin", "WMONGOLIASTANDARDTIME" => "Asia/Hovd",
  "WESTASIASTANDARDTIME" => "Asia/Tashkent", "WESTBANKSTANDARDTIME" => "Asia/Hebron",
  "WESTPACIFICSTANDARDTIME" => "Pacific/Port_Moresby", "YAKUTSKSTANDARDTIME" => "Asia/Yakutsk"
}.freeze

If there's any interest in including this with the gem I'm happy to open up a PR.

timezone = xero.Organisation.all.first.timezone # => "EASTERNSTANDARDTIME"
Time.parse("2017-08-31T17:24:48Z").in_time_zone(TIMEZONES[timezone]) # => Thu, 31 Aug 2017 13:24:48 EDT -04:00

It's very helpful for getting an invoice marked as due on the right date.