Time Zones and City names

Time Zone Names

Time zones (such as "Pacific Time" or "France Time") can be formatted in different ways:

    • "metazone" names, such as "Pacific Time" or "Pacific Standard Time", that can apply to segments of a country or groups of countries.

    • location (country or city) based names, such as "Paris Time" or "Japan Standard Time"

      • These are constructed using patterns (see below), plus Country/Region Names and City Names.

      • When a "metazone" name is absent, a location based name is used as a fallback.

    • raw offsets, like "GMT+10:00"

      • These are constructed using patterns (see below).


  • When translating time zone names, include the Region information if the name can be ambiguous. For example, ā€œCentral timeā€ would be ambiguous without the America_Central region context.

  • When the English name can be ambiguous in your language, use the name that's most commonly used. For example, the English America_Mountain "Mountain time" can be ambiguous and including "Rocky" may be most commonly understood in your language; thus the translation would be for "Rocky Mountain time".

For each of the first two, there are three choices:

    • Winter (standard) time, such as "Atlantic Standard Time"

    • Summer (daylight) time, such as "Atlantic Daylight Time"

    • Generic time, such as "Atlantic Time". This is used for recurring times (such as in a Calendar program) that change between summer and winter.

Time Zone Patterns

The following special patterns are used in formatting timezones.

City Names

Please choose the most neutral grammatical form of the city name. The city name will typically be used to indicate a timezone, either in a menu, or in formatting a time.

In a few cases, what is included in the list of cities for translation is actually a country name, such as the following. In those cases, use the name of the country instead.

    • Costa Rica

    • Cape Verde

    • Faeroe (for the Faroe Islands)


A city may be used in a menu of timezone names, such as:

  • ...

  • United States Time (Los Angeles)

  • United States Time (New York)

  • United Kingdom Time (London)

  • ...

Timezones may also have a simpler format, depending on the language, such as:

  • ...

  • United States (Los Angeles)

  • United States (New York)

  • United Kingdom (London)

  • ...

The city name may also be used in formatted times, such as:

  • 12:51 AM France Time (Paris)

Unique Names

City names must be unique. See Country/Region Names for techniques.