I18n Timezones

Provides timezone translations for Rails applications. Translates ActiveSupport::TimeZone names via I18n so that time_zone_select and similar helpers display localized timezone names.

Why This Gem?

As of Rails 8.x, Rails does not provide native timezone translations. The ActiveSupport::TimeZone#to_s method returns English timezone names regardless of the current locale. This gem fills that gap by overriding to_s to look up translations via I18n.t.

Requirements

• Ruby >= 3.1
• Rails >= 7.0 (or activesupport + railties >= 7.0)

Installation

Add to your Gemfile:

gem 'i18n-timezones'

Translation data is provided by the i18n-timezones-data gem, which is installed automatically as a dependency.

Usage

Timezones are automatically translated to the current locale:

time_zone_select :user, :time_zone, ActiveSupport::TimeZone.us_zones,
                 default: "Pacific Time (US & Canada)"

Or simply:

time_zone_select :user, :time_zone

The :default value also gets translated to the current locale.

You can also use translations directly:

I18n.locale = :de
ActiveSupport::TimeZone["Tokyo"].to_s
# => "(GMT+09:00) Tokio"

I18n.locale = :ja
ActiveSupport::TimeZone["Tokyo"].to_s
# => "(GMT+09:00) 東京"

Supported Locales

Translations are provided for 36 locales covering all 152 Rails timezones:

ar, bn, ca, cs, da, de, el, en, es, eu, fi, fr, he, hi, hr, hu, id, it, ja, ko, ms, nl, no, pl, pt, pt-BR, ro, ru, sq, sv, th, tr, uk, vi, zh-CN, zh-TW

How It Works

This gem uses a Railtie to automatically load translations after Rails initializes. Translations are loaded from the i18n-timezones-data gem via I18n.backend.store_translations, scoped under timezones:.

If your app sets config.i18n.available_locales, only the matching locales will be loaded.

Without Rails

If you're using ActiveSupport without Rails, load translations manually:

require "i18n"
require "yaml"
require "active_support"
require "i18n_timezones/timezone"
require "i18n_timezones_data"

Dir[File.join(I18nTimezonesData.data_dir, "*.yml")].each do |file|
  locale = File.basename(file, ".yml").to_sym
  translations = YAML.safe_load(File.read(file))
  I18n.backend.store_translations(locale, timezones: translations)
end

Contributing

Translation data lives in the i18n-timezones-data repo. To add or fix translations, submit a pull request there.

Running tests

bundle install
bundle exec rspec

Also Available for JavaScript

• i18n-timezones-js — The same translations for JavaScript/TypeScript projects

Known Limitations

• TimeZone#to_s is translated, but TimeZone#name intentionally returns the original English name. The English name is used as a lookup key for translations and must remain stable.

License

MIT