Mapping between rails timezones (names) and their ISO definition on postgres.

rails_pg_timezone_lookup.sql

-- see http://api.rubyonrails.org/classes/ActiveSupport/TimeZone.html MAPPING
WITH timezone_lookup(rails_timezone, pg_timezone) 
AS (
  VALUES 
  ('International Date Line West', 'Pacific/Midway'),
  ('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'),
  ('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')
)
SELECT * FROM timezone_lookup;