[tz] Astrakhan region got approval to change its time zone

Paul Eggert eggert at cs.ucla.edu
Wed Feb 17 00:26:43 UTC 2016

On 02/16/2016 03:08 PM, Matt Johnson wrote:
> Don't people in China use the term "Beijing Time"?

Yes, they use "北京时间" (Beijing Time, which we abbreviate as "CST" for 
China Standard Time because that's what we've done for decades), just as 
people in Russia use "Московское время" (which we abbreviate to MSK for 
even odder historical reasons). But Russia does not have standard names 
or abbreviations for anything other than Moscow time, and in this sense 
Russia is like China (though China is mostly a one-time-zone state so 
the problem of inventing abbreviations mostly does not come up there).

> Even in the US, I think if you said "New York Time", people would know 
> you meant Eastern.

Sure, and if you said "Houston Time" people would know you meant 
Central. But that doesn't mean the time zone is called "Houston Time" or 
is abbreviated "HOUT".

> it would help to define the problem more clearly by understanding the 
> current usage of these abbreviations.  Where are they *actually* needed?

strftime's %Z format. This C-library interface is used by the 'date' 
command to get the time zone, and by lots of higher-level APIs, e.g., 
the current-time-zone function in GNU Emacs. There are other low-level C 
interfaces like tzname, but strftime %Z is the main thing.

> In other words, in what use case(s) would I actually want to use 
> abbreviations from TZDB instead of those from CLDR?

It depends on what you want to do. Ideally, you'd never want to use them 
in a new application. But legacy interfaces like strftime and 
current-time-zone must use them.

> What would be the consequence of just removing the column entirely? 
>  (ok, maybe too drastic, but just for discussion)

strftime %Z would stop working, and lots of old and/or questionable code 
would stop working.

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