如何从TimeZoneInfo获取国家名称

Question

If we have TimeZoneInfo how can we get country name for the selected Timezone.

Example:

Asia/Singapore = Singapore
Asia/Tokyo     = Tokyo
Europe/Moscow  = Russia

Thank you

Answer 1

I see no built in way to do it. TimeZoneInfo class does not have a property or a method which returns a country code. See: https://docs.microsoft.com/en-us/dotnet/api/system.timezoneinfo?view=netframework-4.7.2

The behaviour of TimeZoneInfo is also dependent on the Operating Systems it runs on. See below:

Running the following code on NET Core 2.1 on Windows 10:

TimeZoneInfo localZone = TimeZoneInfo.Local;
Console.WriteLine("Local Time Zone ID: {0}", localZone.Id);
Console.WriteLine("   Display Name is: {0}.", localZone.DisplayName);
Console.WriteLine("   Standard name is: {0}.", localZone.StandardName);
Console.WriteLine("   Daylight saving name is: {0}.", localZone.DaylightName);

Gives output:

Local Time Zone ID: Central Europe Standard Time
Display Name is: (UTC+01:00) Belgrade, Bratislava, Budapest, Ljubljana, Prague.
Standard name is: Central Europe Standard Time.
Daylight saving name is: Central Europe Summer Time.

Running the same code NET Core 2.1 on macOS High Sierra:

Local Time Zone ID: Europe/Budapest
Display Name is: GMT+01:00.
Standard name is: GMT+01:00.
Daylight saving name is: GMT+02:00.

The closest approximation you can implement is:

1. Download a recent copy of tz database. You can use https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

2. Download a copy of country codes. Wikipedia has a list: https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2

3. Implement code that searches your TZ database by TZ name like "Europe/Budapest". This gives you a Country Code. Then search your Country Database with the two letter country code which will get you a Country Name.

This method is not cross platform! And your application must be updated when the tz database of the list of country codes changes.