Is there a list of "current" time zones?

[Philip Howell]

Hi Tim,

In the tzdata tarball is a file called zone.tab.  It lists the current 
time zones grouped by country code.

Cheers,
Phil

Tim Klein wrote:
> I'm new here.  As I look through the tz database, and the archives of 
> this mailing list, I realize what a phenomenal effort you folks have 
> put in, to make all of this information available.  Thank you for all 
> you've done!
>
> A question...
>
> I'm helping to write an application that needs a menu for the user to 
> choose what time zone they live in.  With ~400 time zones in the 
> database, that'd be a pretty daunting pull-down menu.
>
> But as I understand it, a significant fraction of the ~400 time zones 
> exist only for historical reasons.  Since our application will deal 
> only with current and future times, historical distinctions don't 
> matter, and we'd like the menu to show only the subset of time zones 
> that are currently "in effect".  (And we don't mind if it isn't 
> painstakingly accurate or updated in real time.)
>
> Has anyone created such a list?  Or maybe an algorithm (if not code) 
> for generating one from the full database?
>
> I see that this question has come up in the past.  To quote from the 
> archives...
>
> ======
>
>> From: "Andy Lipscomb" <AndyLipscomb at decosimo.com>
>> Perhaps a better term would be "historical" time zones. This would in 
>> fact be a useful distinction, since only a relatively small subset of 
>> the timezones are necessary for applications that look only 
>> forward--these would be the first set to present to a user for 
>> selecting a time zone, with a "show all" option to get the complete 
>> list. (For example, the 50 United States can be covered on a 
>> forward-looking basis by eight zones--New York, Chicago, Denver, 
>> Phoenix, Los Angeles, Anchorage, Adak, and Honolulu. And if one takes 
>> as irrevocable the power of the EU over DST dates, then--for 
>> example--London, Paris, and Helsinki would cover that entire area, 
>> except for the different abbreviations used in the three +0 countries.)
>
> ======
> And...
>
>> From: Paul Eggert [mailto:eggert at CS.UCLA.EDU]
>> Sent: November 6, 2006 12:13 PM
>>
>>>  Is there any way to flag some of the old historical zones such that
>>>  they don't appear when running "tzselect"?
>>
>> We could have a table for people who don't care about historical 
>> times, which maps zone names to "modern" zone names, and tzselect 
>> could have an option to use that table.
>
> ======
>
> Thank you very much for any wisdom on this subject!
>
> Tim Klein
> Dallas, Texas, USA
>
>